diff --git a/src/Makefile.am b/src/Makefile.am
index a57fcb071..7490d8b79 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -152,6 +152,7 @@ BITCOIN_CORE_H = \
   netaddress.h \
   netbase.h \
   netmessagemaker.h \
+  node/transaction.h \
   noui.h \
   optional.h \
   outputtype.h \
@@ -161,6 +162,7 @@ BITCOIN_CORE_H = \
   policy/rbf.h \
   pow.h \
   protocol.h \
+  psbt.h \
   random.h \
   reverse_iterator.h \
   reverselock.h \
@@ -209,6 +211,7 @@ BITCOIN_CORE_H = \
   wallet/db.h \
   wallet/feebumper.h \
   wallet/fees.h \
+  wallet/psbtwallet.h \
   wallet/rpcwallet.h \
   wallet/wallet.h \
   wallet/walletdb.h \
@@ -255,6 +258,7 @@ libbitcoin_server_a_SOURCES = \
   miner.cpp \
   net.cpp \
   net_processing.cpp \
+  node/transaction.cpp \
   noui.cpp \
   outputtype.cpp \
   policy/fees.cpp \
@@ -308,6 +312,7 @@ libbitcoin_wallet_a_SOURCES = \
   wallet/feebumper.cpp \
   wallet/fees.cpp \
   wallet/init.cpp \
+  wallet/psbtwallet.cpp \
   wallet/rpcdump.cpp \
   wallet/rpcwallet.cpp \
   wallet/wallet.cpp \
@@ -421,6 +426,7 @@ libbitcoin_common_a_SOURCES = \
   netaddress.cpp \
   netbase.cpp \
   policy/feerate.cpp \
+  psbt.cpp \
   protocol.cpp \
   scheduler.cpp \
   script/descriptor.cpp \
diff --git a/src/core_io.h b/src/core_io.h
index 6f87161f4..ae377eb6e 100644
--- a/src/core_io.h
+++ b/src/core_io.h
@@ -37,7 +37,11 @@ bool DecodeHexBlockHeader(CBlockHeader&, const std::string& hex_header);
  */
 bool ParseHashStr(const std::string& strHex, uint256& result);
 std::vector<unsigned char> ParseHexUV(const UniValue& v, const std::string& strName);
-NODISCARD bool DecodePSBT(PartiallySignedTransaction& psbt, const std::string& base64_tx, std::string& error);
+
+//! Decode a base64ed PSBT into a PartiallySignedTransaction
+NODISCARD bool DecodeBase64PSBT(PartiallySignedTransaction& decoded_psbt, const std::string& base64_psbt, std::string& error);
+//! Decode a raw (binary blob) PSBT into a PartiallySignedTransaction
+NODISCARD bool DecodeRawPSBT(PartiallySignedTransaction& decoded_psbt, const std::string& raw_psbt, std::string& error);
 int ParseSighashString(const UniValue& sighash);
 
 // core_write.cpp
diff --git a/src/core_read.cpp b/src/core_read.cpp
index 3b82b2853..536a7f4f1 100644
--- a/src/core_read.cpp
+++ b/src/core_read.cpp
@@ -4,6 +4,7 @@
 
 #include <core_io.h>
 
+#include <psbt.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
 #include <script/script.h>
@@ -176,10 +177,20 @@ bool DecodeHexBlk(CBlock& block, const std::string& strHexBlk)
     return true;
 }
 
-bool DecodePSBT(PartiallySignedTransaction& psbt, const std::string& base64_tx, std::string& error)
+bool DecodeBase64PSBT(PartiallySignedTransaction& psbt, const std::string& base64_tx, std::string& error)
 {
-    std::vector<unsigned char> tx_data = DecodeBase64(base64_tx.c_str());
-    CDataStream ss_data(tx_data, SER_NETWORK, PROTOCOL_VERSION);
+    bool invalid;
+    std::string tx_data = DecodeBase64(base64_tx, &invalid);
+    if (invalid) {
+        error = "invalid base64";
+        return false;
+    }
+    return DecodeRawPSBT(psbt, tx_data, error);
+}
+
+bool DecodeRawPSBT(PartiallySignedTransaction& psbt, const std::string& tx_data, std::string& error)
+{
+    CDataStream ss_data(tx_data.data(), tx_data.data() + tx_data.size(), SER_NETWORK, PROTOCOL_VERSION);
     try {
         ss_data >> psbt;
         if (!ss_data.empty()) {
diff --git a/src/node/transaction.cpp b/src/node/transaction.cpp
new file mode 100644
index 000000000..c9cdd0d1c
--- /dev/null
+++ b/src/node/transaction.cpp
@@ -0,0 +1,115 @@
+// Copyright (c) 2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <consensus/validation.h>
+#include <net.h>
+#include <txmempool.h>
+#include <validation.h>
+#include <validationinterface.h>
+#include <node/transaction.h>
+
+#include <future>
+
+const char* TransactionErrorString(const TransactionError err)
+{
+    switch (err) {
+        case TransactionError::OK:
+            return "No error";
+        case TransactionError::MISSING_INPUTS:
+            return "Missing inputs";
+        case TransactionError::ALREADY_IN_CHAIN:
+            return "Transaction already in block chain";
+        case TransactionError::P2P_DISABLED:
+            return "Peer-to-peer functionality missing or disabled";
+        case TransactionError::MEMPOOL_REJECTED:
+            return "Transaction rejected by AcceptToMemoryPool";
+        case TransactionError::MEMPOOL_ERROR:
+            return "AcceptToMemoryPool failed";
+        case TransactionError::INVALID_PSBT:
+            return "PSBT is not sane";
+        case TransactionError::PSBT_MISMATCH:
+            return "PSBTs not compatible (different transactions)";
+        case TransactionError::SIGHASH_MISMATCH:
+            return "Specified sighash value does not match existing value";
+
+        case TransactionError::UNKNOWN_ERROR:
+        default: break;
+    }
+    return "Unknown error";
+}
+
+bool BroadcastTransaction(const CTransactionRef tx, uint256& hashTx, TransactionError& error, std::string& err_string, const bool allowhighfees)
+{
+    std::promise<void> promise;
+    hashTx = tx->GetHash();
+
+    CAmount nMaxRawTxFee = maxTxFee;
+    if (allowhighfees)
+        nMaxRawTxFee = 0;
+
+    { // cs_main scope
+    LOCK(cs_main);
+    CCoinsViewCache &view = *pcoinsTip;
+    bool fHaveChain = false;
+    for (size_t o = 0; !fHaveChain && o < tx->vout.size(); o++) {
+        const Coin& existingCoin = view.AccessCoin(COutPoint(hashTx, o));
+        fHaveChain = !existingCoin.IsSpent();
+    }
+    bool fHaveMempool = mempool.exists(hashTx);
+    if (!fHaveMempool && !fHaveChain) {
+        // push to local node and sync with wallets
+        CValidationState state;
+        bool fMissingInputs;
+        if (!AcceptToMemoryPool(mempool, state, std::move(tx), &fMissingInputs,
+                                nullptr /* plTxnReplaced */, false /* bypass_limits */, nMaxRawTxFee)) {
+            if (state.IsInvalid()) {
+                err_string = FormatStateMessage(state);
+                error = TransactionError::MEMPOOL_REJECTED;
+                return false;
+            } else {
+                if (fMissingInputs) {
+                    error = TransactionError::MISSING_INPUTS;
+                    return false;
+                }
+                err_string = FormatStateMessage(state);
+                error = TransactionError::MEMPOOL_ERROR;
+                return false;
+            }
+        } else {
+            // If wallet is enabled, ensure that the wallet has been made aware
+            // of the new transaction prior to returning. This prevents a race
+            // where a user might call sendrawtransaction with a transaction
+            // to/from their wallet, immediately call some wallet RPC, and get
+            // a stale result because callbacks have not yet been processed.
+            CallFunctionInValidationInterfaceQueue([&promise] {
+                promise.set_value();
+            });
+        }
+    } else if (fHaveChain) {
+        error = TransactionError::ALREADY_IN_CHAIN;
+        return false;
+    } else {
+        // Make sure we don't block forever if re-sending
+        // a transaction already in mempool.
+        promise.set_value();
+    }
+
+    } // cs_main
+
+    promise.get_future().wait();
+
+    if(!g_connman) {
+        error = TransactionError::P2P_DISABLED;
+        return false;
+    }
+
+    CInv inv(MSG_TX, hashTx);
+    g_connman->ForEachNode([&inv](CNode* pnode)
+    {
+        pnode->PushInventory(inv);
+    });
+
+    return true;
+    }
diff --git a/src/node/transaction.h b/src/node/transaction.h
new file mode 100644
index 000000000..3b0cbba98
--- /dev/null
+++ b/src/node/transaction.h
@@ -0,0 +1,43 @@
+// Copyright (c) 2017-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_NODE_TRANSACTION_H
+#define BITCOIN_NODE_TRANSACTION_H
+
+#include <primitives/transaction.h>
+#include <uint256.h>
+
+enum class TransactionError {
+    OK = 0,
+    UNKNOWN_ERROR,
+
+    MISSING_INPUTS,
+    ALREADY_IN_CHAIN,
+    P2P_DISABLED,
+    MEMPOOL_REJECTED,
+    MEMPOOL_ERROR,
+    INVALID_PSBT,
+    PSBT_MISMATCH,
+    SIGHASH_MISMATCH,
+
+    ERROR_COUNT
+};
+
+#define TRANSACTION_ERR_LAST TransactionError::ERROR_COUNT
+
+const char* TransactionErrorString(const TransactionError error);
+
+/**
+ * Broadcast a transaction
+ *
+ * @param[in]  tx the transaction to broadcast
+ * @param[out] &txid the txid of the transaction, if successfully broadcast
+ * @param[out] &error reference to UniValue to fill with error info on failure
+ * @param[out] &err_string reference to std::string to fill with error string if available
+ * @param[in]  allowhighfees whether to allow fees exceeding maxTxFee
+ * return true on success, false on error (and fills in `error`)
+ */
+bool BroadcastTransaction(CTransactionRef tx, uint256& txid, TransactionError& error, std::string& err_string, bool allowhighfees = false);
+
+#endif // BITCOIN_NODE_TRANSACTION_H
diff --git a/src/psbt.cpp b/src/psbt.cpp
new file mode 100644
index 000000000..81633c0cc
--- /dev/null
+++ b/src/psbt.cpp
@@ -0,0 +1,283 @@
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <psbt.h>
+#include <util/strencodings.h>
+
+PartiallySignedTransaction::PartiallySignedTransaction(const CMutableTransaction& tx) : tx(tx)
+{
+    inputs.resize(tx.vin.size());
+    outputs.resize(tx.vout.size());
+}
+
+bool PartiallySignedTransaction::IsNull() const
+{
+    return !tx && inputs.empty() && outputs.empty() && unknown.empty();
+}
+
+bool PartiallySignedTransaction::Merge(const PartiallySignedTransaction& psbt)
+{
+    // Prohibited to merge two PSBTs over different transactions
+    if (tx->GetHash() != psbt.tx->GetHash()) {
+        return false;
+    }
+
+    for (unsigned int i = 0; i < inputs.size(); ++i) {
+        inputs[i].Merge(psbt.inputs[i]);
+    }
+    for (unsigned int i = 0; i < outputs.size(); ++i) {
+        outputs[i].Merge(psbt.outputs[i]);
+    }
+    unknown.insert(psbt.unknown.begin(), psbt.unknown.end());
+
+    return true;
+}
+
+bool PartiallySignedTransaction::IsSane() const
+{
+    for (PSBTInput input : inputs) {
+        if (!input.IsSane()) return false;
+    }
+    return true;
+}
+
+bool PSBTInput::IsNull() const
+{
+    return !non_witness_utxo && witness_utxo.IsNull() && partial_sigs.empty() && unknown.empty() && hd_keypaths.empty() && redeem_script.empty() && witness_script.empty();
+}
+
+void PSBTInput::FillSignatureData(SignatureData& sigdata) const
+{
+    if (!final_script_sig.empty()) {
+        sigdata.scriptSig = final_script_sig;
+        sigdata.complete = true;
+    }
+    if (!final_script_witness.IsNull()) {
+        sigdata.scriptWitness = final_script_witness;
+        sigdata.complete = true;
+    }
+    if (sigdata.complete) {
+        return;
+    }
+
+    sigdata.signatures.insert(partial_sigs.begin(), partial_sigs.end());
+    if (!redeem_script.empty()) {
+        sigdata.redeem_script = redeem_script;
+    }
+    if (!witness_script.empty()) {
+        sigdata.witness_script = witness_script;
+    }
+    for (const auto& key_pair : hd_keypaths) {
+        sigdata.misc_pubkeys.emplace(key_pair.first.GetID(), key_pair);
+    }
+}
+
+void PSBTInput::FromSignatureData(const SignatureData& sigdata)
+{
+    if (sigdata.complete) {
+        partial_sigs.clear();
+        hd_keypaths.clear();
+        redeem_script.clear();
+        witness_script.clear();
+
+        if (!sigdata.scriptSig.empty()) {
+            final_script_sig = sigdata.scriptSig;
+        }
+        if (!sigdata.scriptWitness.IsNull()) {
+            final_script_witness = sigdata.scriptWitness;
+        }
+        return;
+    }
+
+    partial_sigs.insert(sigdata.signatures.begin(), sigdata.signatures.end());
+    if (redeem_script.empty() && !sigdata.redeem_script.empty()) {
+        redeem_script = sigdata.redeem_script;
+    }
+    if (witness_script.empty() && !sigdata.witness_script.empty()) {
+        witness_script = sigdata.witness_script;
+    }
+    for (const auto& entry : sigdata.misc_pubkeys) {
+        hd_keypaths.emplace(entry.second);
+    }
+}
+
+void PSBTInput::Merge(const PSBTInput& input)
+{
+    if (!non_witness_utxo && input.non_witness_utxo) non_witness_utxo = input.non_witness_utxo;
+    if (witness_utxo.IsNull() && !input.witness_utxo.IsNull()) {
+        witness_utxo = input.witness_utxo;
+        non_witness_utxo = nullptr; // Clear out any non-witness utxo when we set a witness one.
+    }
+
+    partial_sigs.insert(input.partial_sigs.begin(), input.partial_sigs.end());
+    hd_keypaths.insert(input.hd_keypaths.begin(), input.hd_keypaths.end());
+    unknown.insert(input.unknown.begin(), input.unknown.end());
+
+    if (redeem_script.empty() && !input.redeem_script.empty()) redeem_script = input.redeem_script;
+    if (witness_script.empty() && !input.witness_script.empty()) witness_script = input.witness_script;
+    if (final_script_sig.empty() && !input.final_script_sig.empty()) final_script_sig = input.final_script_sig;
+    if (final_script_witness.IsNull() && !input.final_script_witness.IsNull()) final_script_witness = input.final_script_witness;
+}
+
+bool PSBTInput::IsSane() const
+{
+    // Cannot have both witness and non-witness utxos
+    if (!witness_utxo.IsNull() && non_witness_utxo) return false;
+
+    // If we have a witness_script or a scriptWitness, we must also have a witness utxo
+    if (!witness_script.empty() && witness_utxo.IsNull()) return false;
+    if (!final_script_witness.IsNull() && witness_utxo.IsNull()) return false;
+
+    return true;
+}
+
+void PSBTOutput::FillSignatureData(SignatureData& sigdata) const
+{
+    if (!redeem_script.empty()) {
+        sigdata.redeem_script = redeem_script;
+    }
+    if (!witness_script.empty()) {
+        sigdata.witness_script = witness_script;
+    }
+    for (const auto& key_pair : hd_keypaths) {
+        sigdata.misc_pubkeys.emplace(key_pair.first.GetID(), key_pair);
+    }
+}
+
+void PSBTOutput::FromSignatureData(const SignatureData& sigdata)
+{
+    if (redeem_script.empty() && !sigdata.redeem_script.empty()) {
+        redeem_script = sigdata.redeem_script;
+    }
+    if (witness_script.empty() && !sigdata.witness_script.empty()) {
+        witness_script = sigdata.witness_script;
+    }
+    for (const auto& entry : sigdata.misc_pubkeys) {
+        hd_keypaths.emplace(entry.second);
+    }
+}
+
+bool PSBTOutput::IsNull() const
+{
+    return redeem_script.empty() && witness_script.empty() && hd_keypaths.empty() && unknown.empty();
+}
+
+void PSBTOutput::Merge(const PSBTOutput& output)
+{
+    hd_keypaths.insert(output.hd_keypaths.begin(), output.hd_keypaths.end());
+    unknown.insert(output.unknown.begin(), output.unknown.end());
+
+    if (redeem_script.empty() && !output.redeem_script.empty()) redeem_script = output.redeem_script;
+    if (witness_script.empty() && !output.witness_script.empty()) witness_script = output.witness_script;
+}
+
+bool PSBTInputSigned(PSBTInput& input)
+{
+    return !input.final_script_sig.empty() || !input.final_script_witness.IsNull();
+}
+
+bool SignPSBTInput(const SigningProvider& provider, PartiallySignedTransaction& psbt, int index, int sighash)
+{
+    PSBTInput& input = psbt.inputs.at(index);
+    const CMutableTransaction& tx = *psbt.tx;
+
+    if (PSBTInputSigned(input)) {
+        return true;
+    }
+
+    // Fill SignatureData with input info
+    SignatureData sigdata;
+    input.FillSignatureData(sigdata);
+
+    // Get UTXO
+    bool require_witness_sig = false;
+    CTxOut utxo;
+
+    // Verify input sanity, which checks that at most one of witness or non-witness utxos is provided.
+    if (!input.IsSane()) {
+        return false;
+    }
+
+    if (input.non_witness_utxo) {
+        // If we're taking our information from a non-witness UTXO, verify that it matches the prevout.
+        COutPoint prevout = tx.vin[index].prevout;
+        if (input.non_witness_utxo->GetHash() != prevout.hash) {
+            return false;
+        }
+        utxo = input.non_witness_utxo->vout[prevout.n];
+    } else if (!input.witness_utxo.IsNull()) {
+        utxo = input.witness_utxo;
+        // When we're taking our information from a witness UTXO, we can't verify it is actually data from
+        // the output being spent. This is safe in case a witness signature is produced (which includes this
+        // information directly in the hash), but not for non-witness signatures. Remember that we require
+        // a witness signature in this situation.
+        require_witness_sig = true;
+    } else {
+        return false;
+    }
+
+    MutableTransactionSignatureCreator creator(&tx, index, utxo.nValue, sighash);
+    sigdata.witness = false;
+    bool sig_complete = ProduceSignature(provider, creator, utxo.scriptPubKey, sigdata);
+    // Verify that a witness signature was produced in case one was required.
+    if (require_witness_sig && !sigdata.witness) return false;
+    input.FromSignatureData(sigdata);
+
+    // If we have a witness signature, use the smaller witness UTXO.
+    if (sigdata.witness) {
+        input.witness_utxo = utxo;
+        input.non_witness_utxo = nullptr;
+    }
+
+    return sig_complete;
+}
+
+bool FinalizePSBT(PartiallySignedTransaction& psbtx)
+{
+    // Finalize input signatures -- in case we have partial signatures that add up to a complete
+    //   signature, but have not combined them yet (e.g. because the combiner that created this
+    //   PartiallySignedTransaction did not understand them), this will combine them into a final
+    //   script.
+    bool complete = true;
+    for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) {
+        complete &= SignPSBTInput(DUMMY_SIGNING_PROVIDER, psbtx, i, SIGHASH_ALL);
+    }
+
+    return complete;
+}
+
+bool FinalizeAndExtractPSBT(PartiallySignedTransaction& psbtx, CMutableTransaction& result)
+{
+    // It's not safe to extract a PSBT that isn't finalized, and there's no easy way to check
+    //   whether a PSBT is finalized without finalizing it, so we just do this.
+    if (!FinalizePSBT(psbtx)) {
+        return false;
+    }
+
+    result = *psbtx.tx;
+    for (unsigned int i = 0; i < result.vin.size(); ++i) {
+        result.vin[i].scriptSig = psbtx.inputs[i].final_script_sig;
+        result.vin[i].scriptWitness = psbtx.inputs[i].final_script_witness;
+    }
+    return true;
+}
+
+bool CombinePSBTs(PartiallySignedTransaction& out, TransactionError& error, const std::vector<PartiallySignedTransaction>& psbtxs)
+{
+    out = psbtxs[0]; // Copy the first one
+
+    // Merge
+    for (auto it = std::next(psbtxs.begin()); it != psbtxs.end(); ++it) {
+        if (!out.Merge(*it)) {
+            error = TransactionError::PSBT_MISMATCH;
+            return false;
+        }
+    }
+    if (!out.IsSane()) {
+        error = TransactionError::INVALID_PSBT;
+        return false;
+    }
+
+    return true;
+}
diff --git a/src/psbt.h b/src/psbt.h
new file mode 100644
index 000000000..e18790322
--- /dev/null
+++ b/src/psbt.h
@@ -0,0 +1,574 @@
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_PSBT_H
+#define BITCOIN_PSBT_H
+
+#include <attributes.h>
+#include <node/transaction.h>
+#include <primitives/transaction.h>
+#include <pubkey.h>
+#include <script/sign.h>
+
+// Magic bytes
+static constexpr uint8_t PSBT_MAGIC_BYTES[5] = {'p', 's', 'b', 't', 0xff};
+
+// Global types
+static constexpr uint8_t PSBT_GLOBAL_UNSIGNED_TX = 0x00;
+
+// Input types
+static constexpr uint8_t PSBT_IN_NON_WITNESS_UTXO = 0x00;
+static constexpr uint8_t PSBT_IN_WITNESS_UTXO = 0x01;
+static constexpr uint8_t PSBT_IN_PARTIAL_SIG = 0x02;
+static constexpr uint8_t PSBT_IN_SIGHASH = 0x03;
+static constexpr uint8_t PSBT_IN_REDEEMSCRIPT = 0x04;
+static constexpr uint8_t PSBT_IN_WITNESSSCRIPT = 0x05;
+static constexpr uint8_t PSBT_IN_BIP32_DERIVATION = 0x06;
+static constexpr uint8_t PSBT_IN_SCRIPTSIG = 0x07;
+static constexpr uint8_t PSBT_IN_SCRIPTWITNESS = 0x08;
+
+// Output types
+static constexpr uint8_t PSBT_OUT_REDEEMSCRIPT = 0x00;
+static constexpr uint8_t PSBT_OUT_WITNESSSCRIPT = 0x01;
+static constexpr uint8_t PSBT_OUT_BIP32_DERIVATION = 0x02;
+
+// The separator is 0x00. Reading this in means that the unserializer can interpret it
+// as a 0 length key which indicates that this is the separator. The separator has no value.
+static constexpr uint8_t PSBT_SEPARATOR = 0x00;
+
+/** A structure for PSBTs which contain per-input information */
+struct PSBTInput
+{
+    CTransactionRef non_witness_utxo;
+    CTxOut witness_utxo;
+    CScript redeem_script;
+    CScript witness_script;
+    CScript final_script_sig;
+    CScriptWitness final_script_witness;
+    std::map<CPubKey, KeyOriginInfo> hd_keypaths;
+    std::map<CKeyID, SigPair> partial_sigs;
+    std::map<std::vector<unsigned char>, std::vector<unsigned char>> unknown;
+    int sighash_type = 0;
+
+    bool IsNull() const;
+    void FillSignatureData(SignatureData& sigdata) const;
+    void FromSignatureData(const SignatureData& sigdata);
+    void Merge(const PSBTInput& input);
+    bool IsSane() const;
+    PSBTInput() {}
+
+    template <typename Stream>
+    inline void Serialize(Stream& s) const {
+        // Write the utxo
+        // If there is a non-witness utxo, then don't add the witness one.
+        if (non_witness_utxo) {
+            SerializeToVector(s, PSBT_IN_NON_WITNESS_UTXO);
+            OverrideStream<Stream> os(&s, s.GetType(), s.GetVersion() | SERIALIZE_TRANSACTION_NO_WITNESS);
+            SerializeToVector(os, non_witness_utxo);
+        } else if (!witness_utxo.IsNull()) {
+            SerializeToVector(s, PSBT_IN_WITNESS_UTXO);
+            SerializeToVector(s, witness_utxo);
+        }
+
+        if (final_script_sig.empty() && final_script_witness.IsNull()) {
+            // Write any partial signatures
+            for (auto sig_pair : partial_sigs) {
+                SerializeToVector(s, PSBT_IN_PARTIAL_SIG, MakeSpan(sig_pair.second.first));
+                s << sig_pair.second.second;
+            }
+
+            // Write the sighash type
+            if (sighash_type > 0) {
+                SerializeToVector(s, PSBT_IN_SIGHASH);
+                SerializeToVector(s, sighash_type);
+            }
+
+            // Write the redeem script
+            if (!redeem_script.empty()) {
+                SerializeToVector(s, PSBT_IN_REDEEMSCRIPT);
+                s << redeem_script;
+            }
+
+            // Write the witness script
+            if (!witness_script.empty()) {
+                SerializeToVector(s, PSBT_IN_WITNESSSCRIPT);
+                s << witness_script;
+            }
+
+            // Write any hd keypaths
+            SerializeHDKeypaths(s, hd_keypaths, PSBT_IN_BIP32_DERIVATION);
+        }
+
+        // Write script sig
+        if (!final_script_sig.empty()) {
+            SerializeToVector(s, PSBT_IN_SCRIPTSIG);
+            s << final_script_sig;
+        }
+        // write script witness
+        if (!final_script_witness.IsNull()) {
+            SerializeToVector(s, PSBT_IN_SCRIPTWITNESS);
+            SerializeToVector(s, final_script_witness.stack);
+        }
+
+        // Write unknown things
+        for (auto& entry : unknown) {
+            s << entry.first;
+            s << entry.second;
+        }
+
+        s << PSBT_SEPARATOR;
+    }
+
+
+    template <typename Stream>
+    inline void Unserialize(Stream& s) {
+        // Read loop
+        bool found_sep = false;
+        while(!s.empty()) {
+            // Read
+            std::vector<unsigned char> key;
+            s >> key;
+
+            // the key is empty if that was actually a separator byte
+            // This is a special case for key lengths 0 as those are not allowed (except for separator)
+            if (key.empty()) {
+                found_sep = true;
+                break;
+            }
+
+            // First byte of key is the type
+            unsigned char type = key[0];
+
+            // Do stuff based on type
+            switch(type) {
+                case PSBT_IN_NON_WITNESS_UTXO:
+                {
+                    if (non_witness_utxo) {
+                        throw std::ios_base::failure("Duplicate Key, input non-witness utxo already provided");
+                    } else if (key.size() != 1) {
+                        throw std::ios_base::failure("Non-witness utxo key is more than one byte type");
+                    }
+                    // Set the stream to unserialize with witness since this is always a valid network transaction
+                    OverrideStream<Stream> os(&s, s.GetType(), s.GetVersion() & ~SERIALIZE_TRANSACTION_NO_WITNESS);
+                    UnserializeFromVector(os, non_witness_utxo);
+                    break;
+                }
+                case PSBT_IN_WITNESS_UTXO:
+                    if (!witness_utxo.IsNull()) {
+                        throw std::ios_base::failure("Duplicate Key, input witness utxo already provided");
+                    } else if (key.size() != 1) {
+                        throw std::ios_base::failure("Witness utxo key is more than one byte type");
+                    }
+                    UnserializeFromVector(s, witness_utxo);
+                    break;
+                case PSBT_IN_PARTIAL_SIG:
+                {
+                    // Make sure that the key is the size of pubkey + 1
+                    if (key.size() != CPubKey::PUBLIC_KEY_SIZE + 1 && key.size() != CPubKey::COMPRESSED_PUBLIC_KEY_SIZE + 1) {
+                        throw std::ios_base::failure("Size of key was not the expected size for the type partial signature pubkey");
+                    }
+                    // Read in the pubkey from key
+                    CPubKey pubkey(key.begin() + 1, key.end());
+                    if (!pubkey.IsFullyValid()) {
+                       throw std::ios_base::failure("Invalid pubkey");
+                    }
+                    if (partial_sigs.count(pubkey.GetID()) > 0) {
+                        throw std::ios_base::failure("Duplicate Key, input partial signature for pubkey already provided");
+                    }
+
+                    // Read in the signature from value
+                    std::vector<unsigned char> sig;
+                    s >> sig;
+
+                    // Add to list
+                    partial_sigs.emplace(pubkey.GetID(), SigPair(pubkey, std::move(sig)));
+                    break;
+                }
+                case PSBT_IN_SIGHASH:
+                    if (sighash_type > 0) {
+                        throw std::ios_base::failure("Duplicate Key, input sighash type already provided");
+                    } else if (key.size() != 1) {
+                        throw std::ios_base::failure("Sighash type key is more than one byte type");
+                    }
+                    UnserializeFromVector(s, sighash_type);
+                    break;
+                case PSBT_IN_REDEEMSCRIPT:
+                {
+                    if (!redeem_script.empty()) {
+                        throw std::ios_base::failure("Duplicate Key, input redeemScript already provided");
+                    } else if (key.size() != 1) {
+                        throw std::ios_base::failure("Input redeemScript key is more than one byte type");
+                    }
+                    s >> redeem_script;
+                    break;
+                }
+                case PSBT_IN_WITNESSSCRIPT:
+                {
+                    if (!witness_script.empty()) {
+                        throw std::ios_base::failure("Duplicate Key, input witnessScript already provided");
+                    } else if (key.size() != 1) {
+                        throw std::ios_base::failure("Input witnessScript key is more than one byte type");
+                    }
+                    s >> witness_script;
+                    break;
+                }
+                case PSBT_IN_BIP32_DERIVATION:
+                {
+                    DeserializeHDKeypaths(s, key, hd_keypaths);
+                    break;
+                }
+                case PSBT_IN_SCRIPTSIG:
+                {
+                    if (!final_script_sig.empty()) {
+                        throw std::ios_base::failure("Duplicate Key, input final scriptSig already provided");
+                    } else if (key.size() != 1) {
+                        throw std::ios_base::failure("Final scriptSig key is more than one byte type");
+                    }
+                    s >> final_script_sig;
+                    break;
+                }
+                case PSBT_IN_SCRIPTWITNESS:
+                {
+                    if (!final_script_witness.IsNull()) {
+                        throw std::ios_base::failure("Duplicate Key, input final scriptWitness already provided");
+                    } else if (key.size() != 1) {
+                        throw std::ios_base::failure("Final scriptWitness key is more than one byte type");
+                    }
+                    UnserializeFromVector(s, final_script_witness.stack);
+                    break;
+                }
+                // Unknown stuff
+                default:
+                    if (unknown.count(key) > 0) {
+                        throw std::ios_base::failure("Duplicate Key, key for unknown value already provided");
+                    }
+                    // Read in the value
+                    std::vector<unsigned char> val_bytes;
+                    s >> val_bytes;
+                    unknown.emplace(std::move(key), std::move(val_bytes));
+                    break;
+            }
+        }
+
+        if (!found_sep) {
+            throw std::ios_base::failure("Separator is missing at the end of an input map");
+        }
+    }
+
+    template <typename Stream>
+    PSBTInput(deserialize_type, Stream& s) {
+        Unserialize(s);
+    }
+};
+
+/** A structure for PSBTs which contains per output information */
+struct PSBTOutput
+{
+    CScript redeem_script;
+    CScript witness_script;
+    std::map<CPubKey, KeyOriginInfo> hd_keypaths;
+    std::map<std::vector<unsigned char>, std::vector<unsigned char>> unknown;
+
+    bool IsNull() const;
+    void FillSignatureData(SignatureData& sigdata) const;
+    void FromSignatureData(const SignatureData& sigdata);
+    void Merge(const PSBTOutput& output);
+    bool IsSane() const;
+    PSBTOutput() {}
+
+    template <typename Stream>
+    inline void Serialize(Stream& s) const {
+        // Write the redeem script
+        if (!redeem_script.empty()) {
+            SerializeToVector(s, PSBT_OUT_REDEEMSCRIPT);
+            s << redeem_script;
+        }
+
+        // Write the witness script
+        if (!witness_script.empty()) {
+            SerializeToVector(s, PSBT_OUT_WITNESSSCRIPT);
+            s << witness_script;
+        }
+
+        // Write any hd keypaths
+        SerializeHDKeypaths(s, hd_keypaths, PSBT_OUT_BIP32_DERIVATION);
+
+        // Write unknown things
+        for (auto& entry : unknown) {
+            s << entry.first;
+            s << entry.second;
+        }
+
+        s << PSBT_SEPARATOR;
+    }
+
+
+    template <typename Stream>
+    inline void Unserialize(Stream& s) {
+        // Read loop
+        bool found_sep = false;
+        while(!s.empty()) {
+            // Read
+            std::vector<unsigned char> key;
+            s >> key;
+
+            // the key is empty if that was actually a separator byte
+            // This is a special case for key lengths 0 as those are not allowed (except for separator)
+            if (key.empty()) {
+                found_sep = true;
+                break;
+            }
+
+            // First byte of key is the type
+            unsigned char type = key[0];
+
+            // Do stuff based on type
+            switch(type) {
+                case PSBT_OUT_REDEEMSCRIPT:
+                {
+                    if (!redeem_script.empty()) {
+                        throw std::ios_base::failure("Duplicate Key, output redeemScript already provided");
+                    } else if (key.size() != 1) {
+                        throw std::ios_base::failure("Output redeemScript key is more than one byte type");
+                    }
+                    s >> redeem_script;
+                    break;
+                }
+                case PSBT_OUT_WITNESSSCRIPT:
+                {
+                    if (!witness_script.empty()) {
+                        throw std::ios_base::failure("Duplicate Key, output witnessScript already provided");
+                    } else if (key.size() != 1) {
+                        throw std::ios_base::failure("Output witnessScript key is more than one byte type");
+                    }
+                    s >> witness_script;
+                    break;
+                }
+                case PSBT_OUT_BIP32_DERIVATION:
+                {
+                    DeserializeHDKeypaths(s, key, hd_keypaths);
+                    break;
+                }
+                // Unknown stuff
+                default: {
+                    if (unknown.count(key) > 0) {
+                        throw std::ios_base::failure("Duplicate Key, key for unknown value already provided");
+                    }
+                    // Read in the value
+                    std::vector<unsigned char> val_bytes;
+                    s >> val_bytes;
+                    unknown.emplace(std::move(key), std::move(val_bytes));
+                    break;
+                }
+            }
+        }
+
+        if (!found_sep) {
+            throw std::ios_base::failure("Separator is missing at the end of an output map");
+        }
+    }
+
+    template <typename Stream>
+    PSBTOutput(deserialize_type, Stream& s) {
+        Unserialize(s);
+    }
+};
+
+/** A version of CTransaction with the PSBT format*/
+struct PartiallySignedTransaction
+{
+    boost::optional<CMutableTransaction> tx;
+    std::vector<PSBTInput> inputs;
+    std::vector<PSBTOutput> outputs;
+    std::map<std::vector<unsigned char>, std::vector<unsigned char>> unknown;
+
+    bool IsNull() const;
+
+    /** Merge psbt into this. The two psbts must have the same underlying CTransaction (i.e. the
+      * same actual Bitcoin transaction.) Returns true if the merge succeeded, false otherwise. */
+    NODISCARD bool Merge(const PartiallySignedTransaction& psbt);
+    bool IsSane() const;
+    PartiallySignedTransaction() {}
+    PartiallySignedTransaction(const PartiallySignedTransaction& psbt_in) : tx(psbt_in.tx), inputs(psbt_in.inputs), outputs(psbt_in.outputs), unknown(psbt_in.unknown) {}
+    explicit PartiallySignedTransaction(const CMutableTransaction& tx);
+
+    template <typename Stream>
+    inline void Serialize(Stream& s) const {
+
+        // magic bytes
+        s << PSBT_MAGIC_BYTES;
+
+        // unsigned tx flag
+        SerializeToVector(s, PSBT_GLOBAL_UNSIGNED_TX);
+
+        // Write serialized tx to a stream
+        OverrideStream<Stream> os(&s, s.GetType(), s.GetVersion() | SERIALIZE_TRANSACTION_NO_WITNESS);
+        SerializeToVector(os, *tx);
+
+        // Write the unknown things
+        for (auto& entry : unknown) {
+            s << entry.first;
+            s << entry.second;
+        }
+
+        // Separator
+        s << PSBT_SEPARATOR;
+
+        // Write inputs
+        for (const PSBTInput& input : inputs) {
+            s << input;
+        }
+        // Write outputs
+        for (const PSBTOutput& output : outputs) {
+            s << output;
+        }
+    }
+
+
+    template <typename Stream>
+    inline void Unserialize(Stream& s) {
+        // Read the magic bytes
+        uint8_t magic[5];
+        s >> magic;
+        if (!std::equal(magic, magic + 5, PSBT_MAGIC_BYTES)) {
+            throw std::ios_base::failure("Invalid PSBT magic bytes");
+        }
+
+        // Read global data
+        bool found_sep = false;
+        while(!s.empty()) {
+            // Read
+            std::vector<unsigned char> key;
+            s >> key;
+
+            // the key is empty if that was actually a separator byte
+            // This is a special case for key lengths 0 as those are not allowed (except for separator)
+            if (key.empty()) {
+                found_sep = true;
+                break;
+            }
+
+            // First byte of key is the type
+            unsigned char type = key[0];
+
+            // Do stuff based on type
+            switch(type) {
+                case PSBT_GLOBAL_UNSIGNED_TX:
+                {
+                    if (tx) {
+                        throw std::ios_base::failure("Duplicate Key, unsigned tx already provided");
+                    } else if (key.size() != 1) {
+                        throw std::ios_base::failure("Global unsigned tx key is more than one byte type");
+                    }
+                    CMutableTransaction mtx;
+                    // Set the stream to serialize with non-witness since this should always be non-witness
+                    OverrideStream<Stream> os(&s, s.GetType(), s.GetVersion() | SERIALIZE_TRANSACTION_NO_WITNESS);
+                    UnserializeFromVector(os, mtx);
+                    tx = std::move(mtx);
+                    // Make sure that all scriptSigs and scriptWitnesses are empty
+                    for (const CTxIn& txin : tx->vin) {
+                        if (!txin.scriptSig.empty() || !txin.scriptWitness.IsNull()) {
+                            throw std::ios_base::failure("Unsigned tx does not have empty scriptSigs and scriptWitnesses.");
+                        }
+                    }
+                    break;
+                }
+                // Unknown stuff
+                default: {
+                    if (unknown.count(key) > 0) {
+                        throw std::ios_base::failure("Duplicate Key, key for unknown value already provided");
+                    }
+                    // Read in the value
+                    std::vector<unsigned char> val_bytes;
+                    s >> val_bytes;
+                    unknown.emplace(std::move(key), std::move(val_bytes));
+                }
+            }
+        }
+
+        if (!found_sep) {
+            throw std::ios_base::failure("Separator is missing at the end of the global map");
+        }
+
+        // Make sure that we got an unsigned tx
+        if (!tx) {
+            throw std::ios_base::failure("No unsigned transcation was provided");
+        }
+
+        // Read input data
+        unsigned int i = 0;
+        while (!s.empty() && i < tx->vin.size()) {
+            PSBTInput input;
+            s >> input;
+            inputs.push_back(input);
+
+            // Make sure the non-witness utxo matches the outpoint
+            if (input.non_witness_utxo && input.non_witness_utxo->GetHash() != tx->vin[i].prevout.hash) {
+                throw std::ios_base::failure("Non-witness UTXO does not match outpoint hash");
+            }
+            ++i;
+        }
+        // Make sure that the number of inputs matches the number of inputs in the transaction
+        if (inputs.size() != tx->vin.size()) {
+            throw std::ios_base::failure("Inputs provided does not match the number of inputs in transaction.");
+        }
+
+        // Read output data
+        i = 0;
+        while (!s.empty() && i < tx->vout.size()) {
+            PSBTOutput output;
+            s >> output;
+            outputs.push_back(output);
+            ++i;
+        }
+        // Make sure that the number of outputs matches the number of outputs in the transaction
+        if (outputs.size() != tx->vout.size()) {
+            throw std::ios_base::failure("Outputs provided does not match the number of outputs in transaction.");
+        }
+        // Sanity check
+        if (!IsSane()) {
+            throw std::ios_base::failure("PSBT is not sane.");
+        }
+    }
+
+    template <typename Stream>
+    PartiallySignedTransaction(deserialize_type, Stream& s) {
+        Unserialize(s);
+    }
+};
+
+/** Checks whether a PSBTInput is already signed. */
+bool PSBTInputSigned(PSBTInput& input);
+
+/** Signs a PSBTInput, verifying that all provided data matches what is being signed. */
+bool SignPSBTInput(const SigningProvider& provider, PartiallySignedTransaction& psbt, int index, int sighash = SIGHASH_ALL);
+
+/**
+ * Finalizes a PSBT if possible, combining partial signatures.
+ *
+ * @param[in,out] &psbtx reference to PartiallySignedTransaction to finalize
+ * return True if the PSBT is now complete, false otherwise
+ */
+bool FinalizePSBT(PartiallySignedTransaction& psbtx);
+
+/**
+ * Finalizes a PSBT if possible, and extracts it to a CMutableTransaction if it could be finalized.
+ *
+ * @param[in]  &psbtx reference to PartiallySignedTransaction
+ * @param[out] result CMutableTransaction representing the complete transaction, if successful
+ * @return True if we successfully extracted the transaction, false otherwise
+ */
+bool FinalizeAndExtractPSBT(PartiallySignedTransaction& psbtx, CMutableTransaction& result);
+
+/**
+ * Combines PSBTs with the same underlying transaction, resulting in a single PSBT with all partial signatures from each input.
+ *
+ * @param[out] &out   the combined PSBT, if successful
+ * @param[out] &error reference to TransactionError to fill with error info on failure
+ * @param[in]  psbtxs the PSBTs to combine
+ * @return True if we successfully combined the transactions, false if they were not compatible
+ */
+bool CombinePSBTs(PartiallySignedTransaction& out, TransactionError& error, const std::vector<PartiallySignedTransaction>& psbtxs);
+
+#endif // BITCOIN_PSBT_H
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index c2f0c7385..7fe73e56d 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -13,10 +13,11 @@
 #include <key_io.h>
 #include <keystore.h>
 #include <merkleblock.h>
-#include <net.h>
+#include <node/transaction.h>
 #include <policy/policy.h>
 #include <policy/rbf.h>
 #include <primitives/transaction.h>
+#include <psbt.h>
 #include <rpc/rawtransaction.h>
 #include <rpc/server.h>
 #include <rpc/util.h>
@@ -24,13 +25,11 @@
 #include <script/script_error.h>
 #include <script/sign.h>
 #include <script/standard.h>
-#include <txmempool.h>
 #include <uint256.h>
 #include <util/strencodings.h>
 #include <validation.h>
 #include <validationinterface.h>
 
-#include <future>
 #include <stdint.h>
 
 #include <univalue.h>
@@ -1041,8 +1040,6 @@ static UniValue sendrawtransaction(const JSONRPCRequest& request)
                 },
             }.ToString());
 
-    std::promise<void> promise;
-
     RPCTypeCheck(request.params, {UniValue::VSTR, UniValue::VBOOL});
 
     // parse hex string from parameter
@@ -1050,67 +1047,17 @@ static UniValue sendrawtransaction(const JSONRPCRequest& request)
     if (!DecodeHexTx(mtx, request.params[0].get_str()))
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed");
     CTransactionRef tx(MakeTransactionRef(std::move(mtx)));
-    const uint256& hashTx = tx->GetHash();
 
-    CAmount nMaxRawTxFee = maxTxFee;
-    if (!request.params[1].isNull() && request.params[1].get_bool())
-        nMaxRawTxFee = 0;
-
-    { // cs_main scope
-    LOCK(cs_main);
-    CCoinsViewCache &view = *pcoinsTip;
-    bool fHaveChain = false;
-    for (size_t o = 0; !fHaveChain && o < tx->vout.size(); o++) {
-        const Coin& existingCoin = view.AccessCoin(COutPoint(hashTx, o));
-        fHaveChain = !existingCoin.IsSpent();
-    }
-    bool fHaveMempool = mempool.exists(hashTx);
-    if (!fHaveMempool && !fHaveChain) {
-        // push to local node and sync with wallets
-        CValidationState state;
-        bool fMissingInputs;
-        if (!AcceptToMemoryPool(mempool, state, std::move(tx), &fMissingInputs,
-                                nullptr /* plTxnReplaced */, false /* bypass_limits */, nMaxRawTxFee)) {
-            if (state.IsInvalid()) {
-                throw JSONRPCError(RPC_TRANSACTION_REJECTED, FormatStateMessage(state));
-            } else {
-                if (fMissingInputs) {
-                    throw JSONRPCError(RPC_TRANSACTION_ERROR, "Missing inputs");
-                }
-                throw JSONRPCError(RPC_TRANSACTION_ERROR, FormatStateMessage(state));
-            }
-        } else {
-            // If wallet is enabled, ensure that the wallet has been made aware
-            // of the new transaction prior to returning. This prevents a race
-            // where a user might call sendrawtransaction with a transaction
-            // to/from their wallet, immediately call some wallet RPC, and get
-            // a stale result because callbacks have not yet been processed.
-            CallFunctionInValidationInterfaceQueue([&promise] {
-                promise.set_value();
-            });
-        }
-    } else if (fHaveChain) {
-        throw JSONRPCError(RPC_TRANSACTION_ALREADY_IN_CHAIN, "transaction already in block chain");
-    } else {
-        // Make sure we don't block forever if re-sending
-        // a transaction already in mempool.
-        promise.set_value();
+    bool allowhighfees = false;
+    if (!request.params[1].isNull()) allowhighfees = request.params[1].get_bool();
+    uint256 txid;
+    TransactionError err;
+    std::string err_string;
+    if (!BroadcastTransaction(tx, txid, err, err_string, allowhighfees)) {
+        throw JSONRPCTransactionError(err, err_string);
     }
 
-    } // cs_main
-
-    promise.get_future().wait();
-
-    if(!g_connman)
-        throw JSONRPCError(RPC_CLIENT_P2P_DISABLED, "Error: Peer-to-peer functionality missing or disabled");
-
-    CInv inv(MSG_TX, hashTx);
-    g_connman->ForEachNode([&inv](CNode* pnode)
-    {
-        pnode->PushInventory(inv);
-    });
-
-    return hashTx.GetHex();
+    return txid.GetHex();
 }
 
 static UniValue testmempoolaccept(const JSONRPCRequest& request)
@@ -1323,7 +1270,7 @@ UniValue decodepsbt(const JSONRPCRequest& request)
     // Unserialize the transactions
     PartiallySignedTransaction psbtx;
     std::string error;
-    if (!DecodePSBT(psbtx, request.params[0].get_str(), error)) {
+    if (!DecodeBase64PSBT(psbtx, request.params[0].get_str(), error)) {
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR, strprintf("TX decode failed %s", error));
     }
 
@@ -1524,23 +1471,16 @@ UniValue combinepsbt(const JSONRPCRequest& request)
     for (unsigned int i = 0; i < txs.size(); ++i) {
         PartiallySignedTransaction psbtx;
         std::string error;
-        if (!DecodePSBT(psbtx, txs[i].get_str(), error)) {
+        if (!DecodeBase64PSBT(psbtx, txs[i].get_str(), error)) {
             throw JSONRPCError(RPC_DESERIALIZATION_ERROR, strprintf("TX decode failed %s", error));
         }
         psbtxs.push_back(psbtx);
     }
 
-    PartiallySignedTransaction merged_psbt(psbtxs[0]); // Copy the first one
-
-    // Merge
-    for (auto it = std::next(psbtxs.begin()); it != psbtxs.end(); ++it) {
-        if (*it != merged_psbt) {
-            throw JSONRPCError(RPC_INVALID_PARAMETER, "PSBTs do not refer to the same transactions.");
-        }
-        merged_psbt.Merge(*it);
-    }
-    if (!merged_psbt.IsSane()) {
-        throw JSONRPCError(RPC_INVALID_PARAMETER, "Merged PSBT is inconsistent");
+    PartiallySignedTransaction merged_psbt;
+    TransactionError error;
+    if (!CombinePSBTs(merged_psbt, error, psbtxs)) {
+        throw JSONRPCTransactionError(error);
     }
 
     UniValue result(UniValue::VOBJ);
@@ -1581,33 +1521,27 @@ UniValue finalizepsbt(const JSONRPCRequest& request)
     // Unserialize the transactions
     PartiallySignedTransaction psbtx;
     std::string error;
-    if (!DecodePSBT(psbtx, request.params[0].get_str(), error)) {
+    if (!DecodeBase64PSBT(psbtx, request.params[0].get_str(), error)) {
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR, strprintf("TX decode failed %s", error));
     }
 
-    // Finalize input signatures -- in case we have partial signatures that add up to a complete
-    //   signature, but have not combined them yet (e.g. because the combiner that created this
-    //   PartiallySignedTransaction did not understand them), this will combine them into a final
-    //   script.
-    bool complete = true;
-    for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) {
-        complete &= SignPSBTInput(DUMMY_SIGNING_PROVIDER, psbtx, i, SIGHASH_ALL);
-    }
+    bool extract = request.params[1].isNull() || (!request.params[1].isNull() && request.params[1].get_bool());
+
+    CMutableTransaction mtx;
+    bool complete = FinalizeAndExtractPSBT(psbtx, mtx);
 
     UniValue result(UniValue::VOBJ);
     CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
-    bool extract = request.params[1].isNull() || (!request.params[1].isNull() && request.params[1].get_bool());
+    std::string result_str;
+
     if (complete && extract) {
-        CMutableTransaction mtx(*psbtx.tx);
-        for (unsigned int i = 0; i < mtx.vin.size(); ++i) {
-            mtx.vin[i].scriptSig = psbtx.inputs[i].final_script_sig;
-            mtx.vin[i].scriptWitness = psbtx.inputs[i].final_script_witness;
-        }
         ssTx << mtx;
-        result.pushKV("hex", HexStr(ssTx.str()));
+        result_str = HexStr(ssTx.str());
+        result.pushKV("hex", result_str);
     } else {
         ssTx << psbtx;
-        result.pushKV("psbt", EncodeBase64(ssTx.str()));
+        result_str = EncodeBase64(ssTx.str());
+        result.pushKV("psbt", result_str);
     }
     result.pushKV("complete", complete);
 
diff --git a/src/rpc/util.cpp b/src/rpc/util.cpp
index ee7f3ca0d..023b4b674 100644
--- a/src/rpc/util.cpp
+++ b/src/rpc/util.cpp
@@ -141,6 +141,34 @@ unsigned int ParseConfirmTarget(const UniValue& value)
     return (unsigned int)target;
 }
 
+RPCErrorCode RPCErrorFromTransactionError(TransactionError terr)
+{
+    switch (terr) {
+        case TransactionError::MEMPOOL_REJECTED:
+            return RPC_TRANSACTION_REJECTED;
+        case TransactionError::ALREADY_IN_CHAIN:
+            return RPC_TRANSACTION_ALREADY_IN_CHAIN;
+        case TransactionError::P2P_DISABLED:
+            return RPC_CLIENT_P2P_DISABLED;
+        case TransactionError::INVALID_PSBT:
+        case TransactionError::PSBT_MISMATCH:
+            return RPC_INVALID_PARAMETER;
+        case TransactionError::SIGHASH_MISMATCH:
+            return RPC_DESERIALIZATION_ERROR;
+        default: break;
+    }
+    return RPC_TRANSACTION_ERROR;
+}
+
+UniValue JSONRPCTransactionError(TransactionError terr, const std::string& err_string)
+{
+    if (err_string.length() > 0) {
+        return JSONRPCError(RPCErrorFromTransactionError(terr), err_string);
+    } else {
+        return JSONRPCError(RPCErrorFromTransactionError(terr), TransactionErrorString(terr));
+    }
+}
+
 struct Section {
     Section(const std::string& left, const std::string& right)
         : m_left{left}, m_right{right} {}
diff --git a/src/rpc/util.h b/src/rpc/util.h
index d895e99c7..1c9ddcdf4 100644
--- a/src/rpc/util.h
+++ b/src/rpc/util.h
@@ -5,6 +5,7 @@
 #ifndef BITCOIN_RPC_UTIL_H
 #define BITCOIN_RPC_UTIL_H
 
+#include <node/transaction.h>
 #include <pubkey.h>
 #include <script/standard.h>
 #include <univalue.h>
@@ -33,6 +34,9 @@ UniValue DescribeAddress(const CTxDestination& dest);
 //! Parse a confirm target option and raise an RPC error if it is invalid.
 unsigned int ParseConfirmTarget(const UniValue& value);
 
+RPCErrorCode RPCErrorFromTransactionError(TransactionError terr);
+UniValue JSONRPCTransactionError(TransactionError terr, const std::string& err_string = "");
+
 struct RPCArg {
     enum class Type {
         OBJ,
diff --git a/src/script/sign.cpp b/src/script/sign.cpp
index 792fb2997..9d6a390ea 100644
--- a/src/script/sign.cpp
+++ b/src/script/sign.cpp
@@ -232,67 +232,6 @@ bool ProduceSignature(const SigningProvider& provider, const BaseSignatureCreato
     return sigdata.complete;
 }
 
-bool PSBTInputSigned(PSBTInput& input)
-{
-    return !input.final_script_sig.empty() || !input.final_script_witness.IsNull();
-}
-
-bool SignPSBTInput(const SigningProvider& provider, PartiallySignedTransaction& psbt, int index, int sighash)
-{
-    PSBTInput& input = psbt.inputs.at(index);
-    const CMutableTransaction& tx = *psbt.tx;
-
-    if (PSBTInputSigned(input)) {
-        return true;
-    }
-
-    // Fill SignatureData with input info
-    SignatureData sigdata;
-    input.FillSignatureData(sigdata);
-
-    // Get UTXO
-    bool require_witness_sig = false;
-    CTxOut utxo;
-
-    // Verify input sanity, which checks that at most one of witness or non-witness utxos is provided.
-    if (!input.IsSane()) {
-        return false;
-    }
-
-    if (input.non_witness_utxo) {
-        // If we're taking our information from a non-witness UTXO, verify that it matches the prevout.
-        COutPoint prevout = tx.vin[index].prevout;
-        if (input.non_witness_utxo->GetHash() != prevout.hash) {
-            return false;
-        }
-        utxo = input.non_witness_utxo->vout[prevout.n];
-    } else if (!input.witness_utxo.IsNull()) {
-        utxo = input.witness_utxo;
-        // When we're taking our information from a witness UTXO, we can't verify it is actually data from
-        // the output being spent. This is safe in case a witness signature is produced (which includes this
-        // information directly in the hash), but not for non-witness signatures. Remember that we require
-        // a witness signature in this situation.
-        require_witness_sig = true;
-    } else {
-        return false;
-    }
-
-    MutableTransactionSignatureCreator creator(&tx, index, utxo.nValue, sighash);
-    sigdata.witness = false;
-    bool sig_complete = ProduceSignature(provider, creator, utxo.scriptPubKey, sigdata);
-    // Verify that a witness signature was produced in case one was required.
-    if (require_witness_sig && !sigdata.witness) return false;
-    input.FromSignatureData(sigdata);
-
-    // If we have a witness signature, use the smaller witness UTXO.
-    if (sigdata.witness) {
-        input.witness_utxo = utxo;
-        input.non_witness_utxo = nullptr;
-    }
-
-    return sig_complete;
-}
-
 class SignatureExtractorChecker final : public BaseSignatureChecker
 {
 private:
@@ -509,166 +448,6 @@ bool IsSolvable(const SigningProvider& provider, const CScript& script)
     return false;
 }
 
-PartiallySignedTransaction::PartiallySignedTransaction(const CMutableTransaction& tx) : tx(tx)
-{
-    inputs.resize(tx.vin.size());
-    outputs.resize(tx.vout.size());
-}
-
-bool PartiallySignedTransaction::IsNull() const
-{
-    return !tx && inputs.empty() && outputs.empty() && unknown.empty();
-}
-
-void PartiallySignedTransaction::Merge(const PartiallySignedTransaction& psbt)
-{
-    for (unsigned int i = 0; i < inputs.size(); ++i) {
-        inputs[i].Merge(psbt.inputs[i]);
-    }
-    for (unsigned int i = 0; i < outputs.size(); ++i) {
-        outputs[i].Merge(psbt.outputs[i]);
-    }
-    unknown.insert(psbt.unknown.begin(), psbt.unknown.end());
-}
-
-bool PartiallySignedTransaction::IsSane() const
-{
-    for (PSBTInput input : inputs) {
-        if (!input.IsSane()) return false;
-    }
-    return true;
-}
-
-bool PSBTInput::IsNull() const
-{
-    return !non_witness_utxo && witness_utxo.IsNull() && partial_sigs.empty() && unknown.empty() && hd_keypaths.empty() && redeem_script.empty() && witness_script.empty();
-}
-
-void PSBTInput::FillSignatureData(SignatureData& sigdata) const
-{
-    if (!final_script_sig.empty()) {
-        sigdata.scriptSig = final_script_sig;
-        sigdata.complete = true;
-    }
-    if (!final_script_witness.IsNull()) {
-        sigdata.scriptWitness = final_script_witness;
-        sigdata.complete = true;
-    }
-    if (sigdata.complete) {
-        return;
-    }
-
-    sigdata.signatures.insert(partial_sigs.begin(), partial_sigs.end());
-    if (!redeem_script.empty()) {
-        sigdata.redeem_script = redeem_script;
-    }
-    if (!witness_script.empty()) {
-        sigdata.witness_script = witness_script;
-    }
-    for (const auto& key_pair : hd_keypaths) {
-        sigdata.misc_pubkeys.emplace(key_pair.first.GetID(), key_pair);
-    }
-}
-
-void PSBTInput::FromSignatureData(const SignatureData& sigdata)
-{
-    if (sigdata.complete) {
-        partial_sigs.clear();
-        hd_keypaths.clear();
-        redeem_script.clear();
-        witness_script.clear();
-
-        if (!sigdata.scriptSig.empty()) {
-            final_script_sig = sigdata.scriptSig;
-        }
-        if (!sigdata.scriptWitness.IsNull()) {
-            final_script_witness = sigdata.scriptWitness;
-        }
-        return;
-    }
-
-    partial_sigs.insert(sigdata.signatures.begin(), sigdata.signatures.end());
-    if (redeem_script.empty() && !sigdata.redeem_script.empty()) {
-        redeem_script = sigdata.redeem_script;
-    }
-    if (witness_script.empty() && !sigdata.witness_script.empty()) {
-        witness_script = sigdata.witness_script;
-    }
-    for (const auto& entry : sigdata.misc_pubkeys) {
-        hd_keypaths.emplace(entry.second);
-    }
-}
-
-void PSBTInput::Merge(const PSBTInput& input)
-{
-    if (!non_witness_utxo && input.non_witness_utxo) non_witness_utxo = input.non_witness_utxo;
-    if (witness_utxo.IsNull() && !input.witness_utxo.IsNull()) {
-        witness_utxo = input.witness_utxo;
-        non_witness_utxo = nullptr; // Clear out any non-witness utxo when we set a witness one.
-    }
-
-    partial_sigs.insert(input.partial_sigs.begin(), input.partial_sigs.end());
-    hd_keypaths.insert(input.hd_keypaths.begin(), input.hd_keypaths.end());
-    unknown.insert(input.unknown.begin(), input.unknown.end());
-
-    if (redeem_script.empty() && !input.redeem_script.empty()) redeem_script = input.redeem_script;
-    if (witness_script.empty() && !input.witness_script.empty()) witness_script = input.witness_script;
-    if (final_script_sig.empty() && !input.final_script_sig.empty()) final_script_sig = input.final_script_sig;
-    if (final_script_witness.IsNull() && !input.final_script_witness.IsNull()) final_script_witness = input.final_script_witness;
-}
-
-bool PSBTInput::IsSane() const
-{
-    // Cannot have both witness and non-witness utxos
-    if (!witness_utxo.IsNull() && non_witness_utxo) return false;
-
-    // If we have a witness_script or a scriptWitness, we must also have a witness utxo
-    if (!witness_script.empty() && witness_utxo.IsNull()) return false;
-    if (!final_script_witness.IsNull() && witness_utxo.IsNull()) return false;
-
-    return true;
-}
-
-void PSBTOutput::FillSignatureData(SignatureData& sigdata) const
-{
-    if (!redeem_script.empty()) {
-        sigdata.redeem_script = redeem_script;
-    }
-    if (!witness_script.empty()) {
-        sigdata.witness_script = witness_script;
-    }
-    for (const auto& key_pair : hd_keypaths) {
-        sigdata.misc_pubkeys.emplace(key_pair.first.GetID(), key_pair);
-    }
-}
-
-void PSBTOutput::FromSignatureData(const SignatureData& sigdata)
-{
-    if (redeem_script.empty() && !sigdata.redeem_script.empty()) {
-        redeem_script = sigdata.redeem_script;
-    }
-    if (witness_script.empty() && !sigdata.witness_script.empty()) {
-        witness_script = sigdata.witness_script;
-    }
-    for (const auto& entry : sigdata.misc_pubkeys) {
-        hd_keypaths.emplace(entry.second);
-    }
-}
-
-bool PSBTOutput::IsNull() const
-{
-    return redeem_script.empty() && witness_script.empty() && hd_keypaths.empty() && unknown.empty();
-}
-
-void PSBTOutput::Merge(const PSBTOutput& output)
-{
-    hd_keypaths.insert(output.hd_keypaths.begin(), output.hd_keypaths.end());
-    unknown.insert(output.unknown.begin(), output.unknown.end());
-
-    if (redeem_script.empty() && !output.redeem_script.empty()) redeem_script = output.redeem_script;
-    if (witness_script.empty() && !output.witness_script.empty()) witness_script = output.witness_script;
-}
-
 bool HidingSigningProvider::GetCScript(const CScriptID& scriptid, CScript& script) const
 {
     return m_provider->GetCScript(scriptid, script);
diff --git a/src/script/sign.h b/src/script/sign.h
index e884f4c48..64eb3eb8e 100644
--- a/src/script/sign.h
+++ b/src/script/sign.h
@@ -123,32 +123,6 @@ struct SignatureData {
     void MergeSignatureData(SignatureData sigdata);
 };
 
-// Magic bytes
-static constexpr uint8_t PSBT_MAGIC_BYTES[5] = {'p', 's', 'b', 't', 0xff};
-
-// Global types
-static constexpr uint8_t PSBT_GLOBAL_UNSIGNED_TX = 0x00;
-
-// Input types
-static constexpr uint8_t PSBT_IN_NON_WITNESS_UTXO = 0x00;
-static constexpr uint8_t PSBT_IN_WITNESS_UTXO = 0x01;
-static constexpr uint8_t PSBT_IN_PARTIAL_SIG = 0x02;
-static constexpr uint8_t PSBT_IN_SIGHASH = 0x03;
-static constexpr uint8_t PSBT_IN_REDEEMSCRIPT = 0x04;
-static constexpr uint8_t PSBT_IN_WITNESSSCRIPT = 0x05;
-static constexpr uint8_t PSBT_IN_BIP32_DERIVATION = 0x06;
-static constexpr uint8_t PSBT_IN_SCRIPTSIG = 0x07;
-static constexpr uint8_t PSBT_IN_SCRIPTWITNESS = 0x08;
-
-// Output types
-static constexpr uint8_t PSBT_OUT_REDEEMSCRIPT = 0x00;
-static constexpr uint8_t PSBT_OUT_WITNESSSCRIPT = 0x01;
-static constexpr uint8_t PSBT_OUT_BIP32_DERIVATION = 0x02;
-
-// The separator is 0x00. Reading this in means that the unserializer can interpret it
-// as a 0 length key which indicates that this is the separator. The separator has no value.
-static constexpr uint8_t PSBT_SEPARATOR = 0x00;
-
 // Takes a stream and multiple arguments and serializes them as if first serialized into a vector and then into the stream
 // The resulting output into the stream has the total serialized length of all of the objects followed by all objects concatenated with each other.
 template<typename Stream, typename... X>
@@ -223,514 +197,6 @@ void SerializeHDKeypaths(Stream& s, const std::map<CPubKey, KeyOriginInfo>& hd_k
     }
 }
 
-/** A structure for PSBTs which contain per-input information */
-struct PSBTInput
-{
-    CTransactionRef non_witness_utxo;
-    CTxOut witness_utxo;
-    CScript redeem_script;
-    CScript witness_script;
-    CScript final_script_sig;
-    CScriptWitness final_script_witness;
-    std::map<CPubKey, KeyOriginInfo> hd_keypaths;
-    std::map<CKeyID, SigPair> partial_sigs;
-    std::map<std::vector<unsigned char>, std::vector<unsigned char>> unknown;
-    int sighash_type = 0;
-
-    bool IsNull() const;
-    void FillSignatureData(SignatureData& sigdata) const;
-    void FromSignatureData(const SignatureData& sigdata);
-    void Merge(const PSBTInput& input);
-    bool IsSane() const;
-    PSBTInput() {}
-
-    template <typename Stream>
-    inline void Serialize(Stream& s) const {
-        // Write the utxo
-        // If there is a non-witness utxo, then don't add the witness one.
-        if (non_witness_utxo) {
-            SerializeToVector(s, PSBT_IN_NON_WITNESS_UTXO);
-            OverrideStream<Stream> os(&s, s.GetType(), s.GetVersion() | SERIALIZE_TRANSACTION_NO_WITNESS);
-            SerializeToVector(os, non_witness_utxo);
-        } else if (!witness_utxo.IsNull()) {
-            SerializeToVector(s, PSBT_IN_WITNESS_UTXO);
-            SerializeToVector(s, witness_utxo);
-        }
-
-        if (final_script_sig.empty() && final_script_witness.IsNull()) {
-            // Write any partial signatures
-            for (auto sig_pair : partial_sigs) {
-                SerializeToVector(s, PSBT_IN_PARTIAL_SIG, MakeSpan(sig_pair.second.first));
-                s << sig_pair.second.second;
-            }
-
-            // Write the sighash type
-            if (sighash_type > 0) {
-                SerializeToVector(s, PSBT_IN_SIGHASH);
-                SerializeToVector(s, sighash_type);
-            }
-
-            // Write the redeem script
-            if (!redeem_script.empty()) {
-                SerializeToVector(s, PSBT_IN_REDEEMSCRIPT);
-                s << redeem_script;
-            }
-
-            // Write the witness script
-            if (!witness_script.empty()) {
-                SerializeToVector(s, PSBT_IN_WITNESSSCRIPT);
-                s << witness_script;
-            }
-
-            // Write any hd keypaths
-            SerializeHDKeypaths(s, hd_keypaths, PSBT_IN_BIP32_DERIVATION);
-        }
-
-        // Write script sig
-        if (!final_script_sig.empty()) {
-            SerializeToVector(s, PSBT_IN_SCRIPTSIG);
-            s << final_script_sig;
-        }
-        // write script witness
-        if (!final_script_witness.IsNull()) {
-            SerializeToVector(s, PSBT_IN_SCRIPTWITNESS);
-            SerializeToVector(s, final_script_witness.stack);
-        }
-
-        // Write unknown things
-        for (auto& entry : unknown) {
-            s << entry.first;
-            s << entry.second;
-        }
-
-        s << PSBT_SEPARATOR;
-    }
-
-
-    template <typename Stream>
-    inline void Unserialize(Stream& s) {
-        // Read loop
-        bool found_sep = false;
-        while(!s.empty()) {
-            // Read
-            std::vector<unsigned char> key;
-            s >> key;
-
-            // the key is empty if that was actually a separator byte
-            // This is a special case for key lengths 0 as those are not allowed (except for separator)
-            if (key.empty()) {
-                found_sep = true;
-                break;
-            }
-
-            // First byte of key is the type
-            unsigned char type = key[0];
-
-            // Do stuff based on type
-            switch(type) {
-                case PSBT_IN_NON_WITNESS_UTXO:
-                {
-                    if (non_witness_utxo) {
-                        throw std::ios_base::failure("Duplicate Key, input non-witness utxo already provided");
-                    } else if (key.size() != 1) {
-                        throw std::ios_base::failure("Non-witness utxo key is more than one byte type");
-                    }
-                    // Set the stream to unserialize with witness since this is always a valid network transaction
-                    OverrideStream<Stream> os(&s, s.GetType(), s.GetVersion() & ~SERIALIZE_TRANSACTION_NO_WITNESS);
-                    UnserializeFromVector(os, non_witness_utxo);
-                    break;
-                }
-                case PSBT_IN_WITNESS_UTXO:
-                    if (!witness_utxo.IsNull()) {
-                        throw std::ios_base::failure("Duplicate Key, input witness utxo already provided");
-                    } else if (key.size() != 1) {
-                        throw std::ios_base::failure("Witness utxo key is more than one byte type");
-                    }
-                    UnserializeFromVector(s, witness_utxo);
-                    break;
-                case PSBT_IN_PARTIAL_SIG:
-                {
-                    // Make sure that the key is the size of pubkey + 1
-                    if (key.size() != CPubKey::PUBLIC_KEY_SIZE + 1 && key.size() != CPubKey::COMPRESSED_PUBLIC_KEY_SIZE + 1) {
-                        throw std::ios_base::failure("Size of key was not the expected size for the type partial signature pubkey");
-                    }
-                    // Read in the pubkey from key
-                    CPubKey pubkey(key.begin() + 1, key.end());
-                    if (!pubkey.IsFullyValid()) {
-                       throw std::ios_base::failure("Invalid pubkey");
-                    }
-                    if (partial_sigs.count(pubkey.GetID()) > 0) {
-                        throw std::ios_base::failure("Duplicate Key, input partial signature for pubkey already provided");
-                    }
-
-                    // Read in the signature from value
-                    std::vector<unsigned char> sig;
-                    s >> sig;
-
-                    // Add to list
-                    partial_sigs.emplace(pubkey.GetID(), SigPair(pubkey, std::move(sig)));
-                    break;
-                }
-                case PSBT_IN_SIGHASH:
-                    if (sighash_type > 0) {
-                        throw std::ios_base::failure("Duplicate Key, input sighash type already provided");
-                    } else if (key.size() != 1) {
-                        throw std::ios_base::failure("Sighash type key is more than one byte type");
-                    }
-                    UnserializeFromVector(s, sighash_type);
-                    break;
-                case PSBT_IN_REDEEMSCRIPT:
-                {
-                    if (!redeem_script.empty()) {
-                        throw std::ios_base::failure("Duplicate Key, input redeemScript already provided");
-                    } else if (key.size() != 1) {
-                        throw std::ios_base::failure("Input redeemScript key is more than one byte type");
-                    }
-                    s >> redeem_script;
-                    break;
-                }
-                case PSBT_IN_WITNESSSCRIPT:
-                {
-                    if (!witness_script.empty()) {
-                        throw std::ios_base::failure("Duplicate Key, input witnessScript already provided");
-                    } else if (key.size() != 1) {
-                        throw std::ios_base::failure("Input witnessScript key is more than one byte type");
-                    }
-                    s >> witness_script;
-                    break;
-                }
-                case PSBT_IN_BIP32_DERIVATION:
-                {
-                    DeserializeHDKeypaths(s, key, hd_keypaths);
-                    break;
-                }
-                case PSBT_IN_SCRIPTSIG:
-                {
-                    if (!final_script_sig.empty()) {
-                        throw std::ios_base::failure("Duplicate Key, input final scriptSig already provided");
-                    } else if (key.size() != 1) {
-                        throw std::ios_base::failure("Final scriptSig key is more than one byte type");
-                    }
-                    s >> final_script_sig;
-                    break;
-                }
-                case PSBT_IN_SCRIPTWITNESS:
-                {
-                    if (!final_script_witness.IsNull()) {
-                        throw std::ios_base::failure("Duplicate Key, input final scriptWitness already provided");
-                    } else if (key.size() != 1) {
-                        throw std::ios_base::failure("Final scriptWitness key is more than one byte type");
-                    }
-                    UnserializeFromVector(s, final_script_witness.stack);
-                    break;
-                }
-                // Unknown stuff
-                default:
-                    if (unknown.count(key) > 0) {
-                        throw std::ios_base::failure("Duplicate Key, key for unknown value already provided");
-                    }
-                    // Read in the value
-                    std::vector<unsigned char> val_bytes;
-                    s >> val_bytes;
-                    unknown.emplace(std::move(key), std::move(val_bytes));
-                    break;
-            }
-        }
-
-        if (!found_sep) {
-            throw std::ios_base::failure("Separator is missing at the end of an input map");
-        }
-    }
-
-    template <typename Stream>
-    PSBTInput(deserialize_type, Stream& s) {
-        Unserialize(s);
-    }
-};
-
-/** A structure for PSBTs which contains per output information */
-struct PSBTOutput
-{
-    CScript redeem_script;
-    CScript witness_script;
-    std::map<CPubKey, KeyOriginInfo> hd_keypaths;
-    std::map<std::vector<unsigned char>, std::vector<unsigned char>> unknown;
-
-    bool IsNull() const;
-    void FillSignatureData(SignatureData& sigdata) const;
-    void FromSignatureData(const SignatureData& sigdata);
-    void Merge(const PSBTOutput& output);
-    bool IsSane() const;
-    PSBTOutput() {}
-
-    template <typename Stream>
-    inline void Serialize(Stream& s) const {
-        // Write the redeem script
-        if (!redeem_script.empty()) {
-            SerializeToVector(s, PSBT_OUT_REDEEMSCRIPT);
-            s << redeem_script;
-        }
-
-        // Write the witness script
-        if (!witness_script.empty()) {
-            SerializeToVector(s, PSBT_OUT_WITNESSSCRIPT);
-            s << witness_script;
-        }
-
-        // Write any hd keypaths
-        SerializeHDKeypaths(s, hd_keypaths, PSBT_OUT_BIP32_DERIVATION);
-
-        // Write unknown things
-        for (auto& entry : unknown) {
-            s << entry.first;
-            s << entry.second;
-        }
-
-        s << PSBT_SEPARATOR;
-    }
-
-
-    template <typename Stream>
-    inline void Unserialize(Stream& s) {
-        // Read loop
-        bool found_sep = false;
-        while(!s.empty()) {
-            // Read
-            std::vector<unsigned char> key;
-            s >> key;
-
-            // the key is empty if that was actually a separator byte
-            // This is a special case for key lengths 0 as those are not allowed (except for separator)
-            if (key.empty()) {
-                found_sep = true;
-                break;
-            }
-
-            // First byte of key is the type
-            unsigned char type = key[0];
-
-            // Do stuff based on type
-            switch(type) {
-                case PSBT_OUT_REDEEMSCRIPT:
-                {
-                    if (!redeem_script.empty()) {
-                        throw std::ios_base::failure("Duplicate Key, output redeemScript already provided");
-                    } else if (key.size() != 1) {
-                        throw std::ios_base::failure("Output redeemScript key is more than one byte type");
-                    }
-                    s >> redeem_script;
-                    break;
-                }
-                case PSBT_OUT_WITNESSSCRIPT:
-                {
-                    if (!witness_script.empty()) {
-                        throw std::ios_base::failure("Duplicate Key, output witnessScript already provided");
-                    } else if (key.size() != 1) {
-                        throw std::ios_base::failure("Output witnessScript key is more than one byte type");
-                    }
-                    s >> witness_script;
-                    break;
-                }
-                case PSBT_OUT_BIP32_DERIVATION:
-                {
-                    DeserializeHDKeypaths(s, key, hd_keypaths);
-                    break;
-                }
-                // Unknown stuff
-                default: {
-                    if (unknown.count(key) > 0) {
-                        throw std::ios_base::failure("Duplicate Key, key for unknown value already provided");
-                    }
-                    // Read in the value
-                    std::vector<unsigned char> val_bytes;
-                    s >> val_bytes;
-                    unknown.emplace(std::move(key), std::move(val_bytes));
-                    break;
-                }
-            }
-        }
-
-        if (!found_sep) {
-            throw std::ios_base::failure("Separator is missing at the end of an output map");
-        }
-    }
-
-    template <typename Stream>
-    PSBTOutput(deserialize_type, Stream& s) {
-        Unserialize(s);
-    }
-};
-
-/** A version of CTransaction with the PSBT format*/
-struct PartiallySignedTransaction
-{
-    boost::optional<CMutableTransaction> tx;
-    std::vector<PSBTInput> inputs;
-    std::vector<PSBTOutput> outputs;
-    std::map<std::vector<unsigned char>, std::vector<unsigned char>> unknown;
-
-    bool IsNull() const;
-    void Merge(const PartiallySignedTransaction& psbt);
-    bool IsSane() const;
-    PartiallySignedTransaction() {}
-    PartiallySignedTransaction(const PartiallySignedTransaction& psbt_in) : tx(psbt_in.tx), inputs(psbt_in.inputs), outputs(psbt_in.outputs), unknown(psbt_in.unknown) {}
-    explicit PartiallySignedTransaction(const CMutableTransaction& tx);
-
-    // Only checks if they refer to the same transaction
-    friend bool operator==(const PartiallySignedTransaction& a, const PartiallySignedTransaction &b)
-    {
-        return a.tx->GetHash() == b.tx->GetHash();
-    }
-    friend bool operator!=(const PartiallySignedTransaction& a, const PartiallySignedTransaction &b)
-    {
-        return !(a == b);
-    }
-
-    template <typename Stream>
-    inline void Serialize(Stream& s) const {
-
-        // magic bytes
-        s << PSBT_MAGIC_BYTES;
-
-        // unsigned tx flag
-        SerializeToVector(s, PSBT_GLOBAL_UNSIGNED_TX);
-
-        // Write serialized tx to a stream
-        OverrideStream<Stream> os(&s, s.GetType(), s.GetVersion() | SERIALIZE_TRANSACTION_NO_WITNESS);
-        SerializeToVector(os, *tx);
-
-        // Write the unknown things
-        for (auto& entry : unknown) {
-            s << entry.first;
-            s << entry.second;
-        }
-
-        // Separator
-        s << PSBT_SEPARATOR;
-
-        // Write inputs
-        for (const PSBTInput& input : inputs) {
-            s << input;
-        }
-        // Write outputs
-        for (const PSBTOutput& output : outputs) {
-            s << output;
-        }
-    }
-
-
-    template <typename Stream>
-    inline void Unserialize(Stream& s) {
-        // Read the magic bytes
-        uint8_t magic[5];
-        s >> magic;
-        if (!std::equal(magic, magic + 5, PSBT_MAGIC_BYTES)) {
-            throw std::ios_base::failure("Invalid PSBT magic bytes");
-        }
-
-        // Read global data
-        bool found_sep = false;
-        while(!s.empty()) {
-            // Read
-            std::vector<unsigned char> key;
-            s >> key;
-
-            // the key is empty if that was actually a separator byte
-            // This is a special case for key lengths 0 as those are not allowed (except for separator)
-            if (key.empty()) {
-                found_sep = true;
-                break;
-            }
-
-            // First byte of key is the type
-            unsigned char type = key[0];
-
-            // Do stuff based on type
-            switch(type) {
-                case PSBT_GLOBAL_UNSIGNED_TX:
-                {
-                    if (tx) {
-                        throw std::ios_base::failure("Duplicate Key, unsigned tx already provided");
-                    } else if (key.size() != 1) {
-                        throw std::ios_base::failure("Global unsigned tx key is more than one byte type");
-                    }
-                    CMutableTransaction mtx;
-                    // Set the stream to serialize with non-witness since this should always be non-witness
-                    OverrideStream<Stream> os(&s, s.GetType(), s.GetVersion() | SERIALIZE_TRANSACTION_NO_WITNESS);
-                    UnserializeFromVector(os, mtx);
-                    tx = std::move(mtx);
-                    // Make sure that all scriptSigs and scriptWitnesses are empty
-                    for (const CTxIn& txin : tx->vin) {
-                        if (!txin.scriptSig.empty() || !txin.scriptWitness.IsNull()) {
-                            throw std::ios_base::failure("Unsigned tx does not have empty scriptSigs and scriptWitnesses.");
-                        }
-                    }
-                    break;
-                }
-                // Unknown stuff
-                default: {
-                    if (unknown.count(key) > 0) {
-                        throw std::ios_base::failure("Duplicate Key, key for unknown value already provided");
-                    }
-                    // Read in the value
-                    std::vector<unsigned char> val_bytes;
-                    s >> val_bytes;
-                    unknown.emplace(std::move(key), std::move(val_bytes));
-                }
-            }
-        }
-
-        if (!found_sep) {
-            throw std::ios_base::failure("Separator is missing at the end of the global map");
-        }
-
-        // Make sure that we got an unsigned tx
-        if (!tx) {
-            throw std::ios_base::failure("No unsigned transcation was provided");
-        }
-
-        // Read input data
-        unsigned int i = 0;
-        while (!s.empty() && i < tx->vin.size()) {
-            PSBTInput input;
-            s >> input;
-            inputs.push_back(input);
-
-            // Make sure the non-witness utxo matches the outpoint
-            if (input.non_witness_utxo && input.non_witness_utxo->GetHash() != tx->vin[i].prevout.hash) {
-                throw std::ios_base::failure("Non-witness UTXO does not match outpoint hash");
-            }
-            ++i;
-        }
-        // Make sure that the number of inputs matches the number of inputs in the transaction
-        if (inputs.size() != tx->vin.size()) {
-            throw std::ios_base::failure("Inputs provided does not match the number of inputs in transaction.");
-        }
-
-        // Read output data
-        i = 0;
-        while (!s.empty() && i < tx->vout.size()) {
-            PSBTOutput output;
-            s >> output;
-            outputs.push_back(output);
-            ++i;
-        }
-        // Make sure that the number of outputs matches the number of outputs in the transaction
-        if (outputs.size() != tx->vout.size()) {
-            throw std::ios_base::failure("Outputs provided does not match the number of outputs in transaction.");
-        }
-        // Sanity check
-        if (!IsSane()) {
-            throw std::ios_base::failure("PSBT is not sane.");
-        }
-    }
-
-    template <typename Stream>
-    PartiallySignedTransaction(deserialize_type, Stream& s) {
-        Unserialize(s);
-    }
-};
-
 /** Produce a script signature using a generic signature creator. */
 bool ProduceSignature(const SigningProvider& provider, const BaseSignatureCreator& creator, const CScript& scriptPubKey, SignatureData& sigdata);
 
@@ -738,12 +204,6 @@ bool ProduceSignature(const SigningProvider& provider, const BaseSignatureCreato
 bool SignSignature(const SigningProvider &provider, const CScript& fromPubKey, CMutableTransaction& txTo, unsigned int nIn, const CAmount& amount, int nHashType);
 bool SignSignature(const SigningProvider &provider, const CTransaction& txFrom, CMutableTransaction& txTo, unsigned int nIn, int nHashType);
 
-/** Checks whether a PSBTInput is already signed. */
-bool PSBTInputSigned(PSBTInput& input);
-
-/** Signs a PSBTInput, verifying that all provided data matches what is being signed. */
-bool SignPSBTInput(const SigningProvider& provider, PartiallySignedTransaction& psbt, int index, int sighash = SIGHASH_ALL);
-
 /** Extract signature data from a transaction input, and insert it. */
 SignatureData DataFromTransaction(const CMutableTransaction& tx, unsigned int nIn, const CTxOut& txout);
 void UpdateInput(CTxIn& input, const SignatureData& data);
diff --git a/src/util/strencodings.cpp b/src/util/strencodings.cpp
index fedeeac39..b55547bc6 100644
--- a/src/util/strencodings.cpp
+++ b/src/util/strencodings.cpp
@@ -141,7 +141,7 @@ std::string EncodeBase64(const std::string& str)
     return EncodeBase64((const unsigned char*)str.c_str(), str.size());
 }
 
-std::vector<unsigned char> DecodeBase64(const char* p, bool* pfInvalid)
+std::vector<unsigned char> DecodeBase64(const char* p, bool* pf_invalid)
 {
     static const int decode64_table[256] =
     {
@@ -183,14 +183,14 @@ std::vector<unsigned char> DecodeBase64(const char* p, bool* pfInvalid)
         ++p;
     }
     valid = valid && (p - e) % 4 == 0 && p - q < 4;
-    if (pfInvalid) *pfInvalid = !valid;
+    if (pf_invalid) *pf_invalid = !valid;
 
     return ret;
 }
 
-std::string DecodeBase64(const std::string& str)
+std::string DecodeBase64(const std::string& str, bool* pf_invalid)
 {
-    std::vector<unsigned char> vchRet = DecodeBase64(str.c_str());
+    std::vector<unsigned char> vchRet = DecodeBase64(str.c_str(), pf_invalid);
     return std::string((const char*)vchRet.data(), vchRet.size());
 }
 
@@ -210,7 +210,7 @@ std::string EncodeBase32(const std::string& str)
     return EncodeBase32((const unsigned char*)str.c_str(), str.size());
 }
 
-std::vector<unsigned char> DecodeBase32(const char* p, bool* pfInvalid)
+std::vector<unsigned char> DecodeBase32(const char* p, bool* pf_invalid)
 {
     static const int decode32_table[256] =
     {
@@ -252,14 +252,14 @@ std::vector<unsigned char> DecodeBase32(const char* p, bool* pfInvalid)
         ++p;
     }
     valid = valid && (p - e) % 8 == 0 && p - q < 8;
-    if (pfInvalid) *pfInvalid = !valid;
+    if (pf_invalid) *pf_invalid = !valid;
 
     return ret;
 }
 
-std::string DecodeBase32(const std::string& str)
+std::string DecodeBase32(const std::string& str, bool* pf_invalid)
 {
-    std::vector<unsigned char> vchRet = DecodeBase32(str.c_str());
+    std::vector<unsigned char> vchRet = DecodeBase32(str.c_str(), pf_invalid);
     return std::string((const char*)vchRet.data(), vchRet.size());
 }
 
diff --git a/src/util/strencodings.h b/src/util/strencodings.h
index e392055f2..59eefff56 100644
--- a/src/util/strencodings.h
+++ b/src/util/strencodings.h
@@ -44,12 +44,12 @@ bool IsHex(const std::string& str);
 * Return true if the string is a hex number, optionally prefixed with "0x"
 */
 bool IsHexNumber(const std::string& str);
-std::vector<unsigned char> DecodeBase64(const char* p, bool* pfInvalid = nullptr);
-std::string DecodeBase64(const std::string& str);
+std::vector<unsigned char> DecodeBase64(const char* p, bool* pf_invalid = nullptr);
+std::string DecodeBase64(const std::string& str, bool* pf_invalid = nullptr);
 std::string EncodeBase64(const unsigned char* pch, size_t len);
 std::string EncodeBase64(const std::string& str);
-std::vector<unsigned char> DecodeBase32(const char* p, bool* pfInvalid = nullptr);
-std::string DecodeBase32(const std::string& str);
+std::vector<unsigned char> DecodeBase32(const char* p, bool* pf_invalid = nullptr);
+std::string DecodeBase32(const std::string& str, bool* pf_invalid = nullptr);
 std::string EncodeBase32(const unsigned char* pch, size_t len);
 std::string EncodeBase32(const std::string& str);
 
diff --git a/src/wallet/psbtwallet.cpp b/src/wallet/psbtwallet.cpp
new file mode 100644
index 000000000..761e7b7dd
--- /dev/null
+++ b/src/wallet/psbtwallet.cpp
@@ -0,0 +1,62 @@
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <wallet/psbtwallet.h>
+
+bool FillPSBT(const CWallet* pwallet, PartiallySignedTransaction& psbtx, TransactionError& error, bool& complete, int sighash_type, bool sign, bool bip32derivs)
+{
+    LOCK(pwallet->cs_wallet);
+    // Get all of the previous transactions
+    complete = true;
+    for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) {
+        const CTxIn& txin = psbtx.tx->vin[i];
+        PSBTInput& input = psbtx.inputs.at(i);
+
+        if (PSBTInputSigned(input)) {
+            continue;
+        }
+
+        // Verify input looks sane. This will check that we have at most one uxto, witness or non-witness.
+        if (!input.IsSane()) {
+            error = TransactionError::INVALID_PSBT;
+            return false;
+        }
+
+        // If we have no utxo, grab it from the wallet.
+        if (!input.non_witness_utxo && input.witness_utxo.IsNull()) {
+            const uint256& txhash = txin.prevout.hash;
+            const auto it = pwallet->mapWallet.find(txhash);
+            if (it != pwallet->mapWallet.end()) {
+                const CWalletTx& wtx = it->second;
+                // We only need the non_witness_utxo, which is a superset of the witness_utxo.
+                //   The signing code will switch to the smaller witness_utxo if this is ok.
+                input.non_witness_utxo = wtx.tx;
+            }
+        }
+
+        // Get the Sighash type
+        if (sign && input.sighash_type > 0 && input.sighash_type != sighash_type) {
+            error = TransactionError::SIGHASH_MISMATCH;
+            return false;
+        }
+
+        complete &= SignPSBTInput(HidingSigningProvider(pwallet, !sign, !bip32derivs), psbtx, i, sighash_type);
+    }
+
+    // Fill in the bip32 keypaths and redeemscripts for the outputs so that hardware wallets can identify change
+    for (unsigned int i = 0; i < psbtx.tx->vout.size(); ++i) {
+        const CTxOut& out = psbtx.tx->vout.at(i);
+        PSBTOutput& psbt_out = psbtx.outputs.at(i);
+
+        // Fill a SignatureData with output info
+        SignatureData sigdata;
+        psbt_out.FillSignatureData(sigdata);
+
+        MutableTransactionSignatureCreator creator(psbtx.tx.get_ptr(), 0, out.nValue, 1);
+        ProduceSignature(HidingSigningProvider(pwallet, true, !bip32derivs), creator, out.scriptPubKey, sigdata);
+        psbt_out.FromSignatureData(sigdata);
+    }
+
+    return true;
+}
diff --git a/src/wallet/psbtwallet.h b/src/wallet/psbtwallet.h
new file mode 100644
index 000000000..b679f5c6b
--- /dev/null
+++ b/src/wallet/psbtwallet.h
@@ -0,0 +1,36 @@
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_WALLET_PSBTWALLET_H
+#define BITCOIN_WALLET_PSBTWALLET_H
+
+#include <node/transaction.h>
+#include <psbt.h>
+#include <primitives/transaction.h>
+#include <wallet/wallet.h>
+
+/**
+ * Fills out a PSBT with information from the wallet. Fills in UTXOs if we have
+ * them. Tries to sign if sign=true. Sets `complete` if the PSBT is now complete
+ * (i.e. has all required signatures or signature-parts, and is ready to
+ * finalize.) Sets `error` and returns false if something goes wrong.
+ *
+ * @param[in]  pwallet pointer to a wallet
+ * @param[in]  &psbtx reference to PartiallySignedTransaction to fill in
+ * @param[out] &error reference to UniValue to fill with error info on failure
+ * @param[out] &complete indicates whether the PSBT is now complete
+ * @param[in]  sighash_type the sighash type to use when signing (if PSBT does not specify)
+ * @param[in]  sign whether to sign or not
+ * @param[in]  bip32derivs whether to fill in bip32 derivation information if available
+ * return true on success, false on error (and fills in `error`)
+ */
+bool FillPSBT(const CWallet* pwallet,
+              PartiallySignedTransaction& psbtx,
+              TransactionError& error,
+              bool& complete,
+              int sighash_type = 1 /* SIGHASH_ALL */,
+              bool sign = true,
+              bool bip32derivs = false);
+
+#endif // BITCOIN_WALLET_PSBTWALLET_H
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index e836f5079..9e362cf16 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -13,6 +13,7 @@
 #include <validation.h>
 #include <key_io.h>
 #include <net.h>
+#include <node/transaction.h>
 #include <outputtype.h>
 #include <policy/feerate.h>
 #include <policy/fees.h>
@@ -30,6 +31,7 @@
 #include <util/moneystr.h>
 #include <wallet/coincontrol.h>
 #include <wallet/feebumper.h>
+#include <wallet/psbtwallet.h>
 #include <wallet/rpcwallet.h>
 #include <wallet/wallet.h>
 #include <wallet/walletdb.h>
@@ -3938,60 +3940,6 @@ void AddKeypathToMap(const CWallet* pwallet, const CKeyID& keyID, std::map<CPubK
     hd_keypaths.emplace(vchPubKey, std::move(info));
 }
 
-bool FillPSBT(const CWallet* pwallet, PartiallySignedTransaction& psbtx, int sighash_type, bool sign, bool bip32derivs)
-{
-    LOCK(pwallet->cs_wallet);
-    // Get all of the previous transactions
-    bool complete = true;
-    for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) {
-        const CTxIn& txin = psbtx.tx->vin[i];
-        PSBTInput& input = psbtx.inputs.at(i);
-
-        if (PSBTInputSigned(input)) {
-            continue;
-        }
-
-        // Verify input looks sane. This will check that we have at most one uxto, witness or non-witness.
-        if (!input.IsSane()) {
-            throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "PSBT input is not sane.");
-        }
-
-        // If we have no utxo, grab it from the wallet.
-        if (!input.non_witness_utxo && input.witness_utxo.IsNull()) {
-            const uint256& txhash = txin.prevout.hash;
-            const auto it = pwallet->mapWallet.find(txhash);
-            if (it != pwallet->mapWallet.end()) {
-                const CWalletTx& wtx = it->second;
-                // We only need the non_witness_utxo, which is a superset of the witness_utxo.
-                //   The signing code will switch to the smaller witness_utxo if this is ok.
-                input.non_witness_utxo = wtx.tx;
-            }
-        }
-
-        // Get the Sighash type
-        if (sign && input.sighash_type > 0 && input.sighash_type != sighash_type) {
-            throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Specified Sighash and sighash in PSBT do not match.");
-        }
-
-        complete &= SignPSBTInput(HidingSigningProvider(pwallet, !sign, !bip32derivs), psbtx, i, sighash_type);
-    }
-
-    // Fill in the bip32 keypaths and redeemscripts for the outputs so that hardware wallets can identify change
-    for (unsigned int i = 0; i < psbtx.tx->vout.size(); ++i) {
-        const CTxOut& out = psbtx.tx->vout.at(i);
-        PSBTOutput& psbt_out = psbtx.outputs.at(i);
-
-        // Fill a SignatureData with output info
-        SignatureData sigdata;
-        psbt_out.FillSignatureData(sigdata);
-
-        MutableTransactionSignatureCreator creator(psbtx.tx.get_ptr(), 0, out.nValue, 1);
-        ProduceSignature(HidingSigningProvider(pwallet, true, !bip32derivs), creator, out.scriptPubKey, sigdata);
-        psbt_out.FromSignatureData(sigdata);
-    }
-    return complete;
-}
-
 UniValue walletprocesspsbt(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
@@ -4036,7 +3984,7 @@ UniValue walletprocesspsbt(const JSONRPCRequest& request)
     // Unserialize the transaction
     PartiallySignedTransaction psbtx;
     std::string error;
-    if (!DecodePSBT(psbtx, request.params[0].get_str(), error)) {
+    if (!DecodeBase64PSBT(psbtx, request.params[0].get_str(), error)) {
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR, strprintf("TX decode failed %s", error));
     }
 
@@ -4046,7 +3994,11 @@ UniValue walletprocesspsbt(const JSONRPCRequest& request)
     // Fill transaction with our data and also sign
     bool sign = request.params[1].isNull() ? true : request.params[1].get_bool();
     bool bip32derivs = request.params[3].isNull() ? false : request.params[3].get_bool();
-    bool complete = FillPSBT(pwallet, psbtx, nHashType, sign, bip32derivs);
+    bool complete = true;
+    TransactionError err;
+    if (!FillPSBT(pwallet, psbtx, err, complete, nHashType, sign, bip32derivs)) {
+        throw JSONRPCTransactionError(err);
+    }
 
     UniValue result(UniValue::VOBJ);
     CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
@@ -4160,7 +4112,11 @@ UniValue walletcreatefundedpsbt(const JSONRPCRequest& request)
 
     // Fill transaction with out data but don't sign
     bool bip32derivs = request.params[4].isNull() ? false : request.params[4].get_bool();
-    FillPSBT(pwallet, psbtx, 1, false, bip32derivs);
+    bool complete = true;
+    TransactionError err;
+    if (!FillPSBT(pwallet, psbtx, err, complete, 1, false, bip32derivs)) {
+        throw JSONRPCTransactionError(err);
+    }
 
     // Serialize the PSBT
     CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
diff --git a/src/wallet/rpcwallet.h b/src/wallet/rpcwallet.h
index abd775087..58053bde5 100644
--- a/src/wallet/rpcwallet.h
+++ b/src/wallet/rpcwallet.h
@@ -30,5 +30,4 @@ bool EnsureWalletIsAvailable(CWallet *, bool avoidException);
 
 UniValue getaddressinfo(const JSONRPCRequest& request);
 UniValue signrawtransactionwithwallet(const JSONRPCRequest& request);
-bool FillPSBT(const CWallet* pwallet, PartiallySignedTransaction& psbtx, int sighash_type = 1 /* SIGHASH_ALL */, bool sign = true, bool bip32derivs = false);
 #endif //BITCOIN_WALLET_RPCWALLET_H
diff --git a/src/wallet/test/psbt_wallet_tests.cpp b/src/wallet/test/psbt_wallet_tests.cpp
index 9918eeb89..e89d4121b 100644
--- a/src/wallet/test/psbt_wallet_tests.cpp
+++ b/src/wallet/test/psbt_wallet_tests.cpp
@@ -5,6 +5,7 @@
 #include <key_io.h>
 #include <script/sign.h>
 #include <util/strencodings.h>
+#include <wallet/psbtwallet.h>
 #include <wallet/rpcwallet.h>
 #include <wallet/wallet.h>
 #include <univalue.h>
@@ -60,7 +61,9 @@ BOOST_AUTO_TEST_CASE(psbt_updater_test)
     ssData >> psbtx;
 
     // Fill transaction with our data
-    FillPSBT(&m_wallet, psbtx, SIGHASH_ALL, false, true);
+    TransactionError err;
+    bool complete = true;
+    FillPSBT(&m_wallet, psbtx, err, complete, SIGHASH_ALL, false, true);
 
     // Get the final tx
     CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
diff --git a/test/functional/rpc_psbt.py b/test/functional/rpc_psbt.py
index a82a5d020..c98f10582 100755
--- a/test/functional/rpc_psbt.py
+++ b/test/functional/rpc_psbt.py
@@ -293,5 +293,8 @@ class PSBTTest(BitcoinTestFramework):
         psbt = self.nodes[1].walletcreatefundedpsbt([], [{p2pkh : 1}], 0, {"includeWatching" : True}, True)
         self.nodes[0].decodepsbt(psbt['psbt'])
 
+        # Test decoding error: invalid base64
+        assert_raises_rpc_error(-22, "TX decode failed invalid base64", self.nodes[0].decodepsbt, ";definitely not base64;")
+
 if __name__ == '__main__':
     PSBTTest().main()