diff --git a/db/prefixes/prefixes.go b/db/prefixes/prefixes.go
index d52f404..5c5a132 100644
--- a/db/prefixes/prefixes.go
+++ b/db/prefixes/prefixes.go
@@ -525,9 +525,9 @@ class ClaimExpirationValue(typing.NamedTuple):
 
 type ClaimExpirationKey struct {
 	Prefix     []byte `json:"prefix"`
-	Expiration int32  `json:"expiration"`
-	TxNum      int32  `json:"tx_num"`
-	Position   int32  `json:"position"`
+	Expiration uint32 `json:"expiration"`
+	TxNum      uint32 `json:"tx_num"`
+	Position   uint16 `json:"position"`
 }
 
 type ClaimExpirationValue struct {
@@ -535,6 +535,96 @@ type ClaimExpirationValue struct {
 	NormalizedName string `json:"normalized_name"`
 }
 
+func (k *ClaimExpirationKey) PackKey() []byte {
+	prefixLen := 1
+	// b'>LLH'
+	n := prefixLen + 4 + 4 + 2
+	key := make([]byte, n)
+	copy(key, k.Prefix)
+	binary.BigEndian.PutUint32(key[prefixLen:], k.Expiration)
+	binary.BigEndian.PutUint32(key[prefixLen+4:], k.TxNum)
+	binary.BigEndian.PutUint16(key[prefixLen+8:], k.Position)
+
+	return key
+}
+
+func (v *ClaimExpirationValue) PackValue() []byte {
+	nameLen := len(v.NormalizedName)
+	n := 20 + 2 + nameLen
+	value := make([]byte, n)
+	copy(value, v.ClaimHash)
+	binary.BigEndian.PutUint16(value[20:], uint16(nameLen))
+	copy(value[22:], []byte(v.NormalizedName))
+
+	return value
+}
+
+func ClaimExpirationKeyPackPartialNFields(nFields int) func(*ClaimExpirationKey) []byte {
+	return func(u *ClaimExpirationKey) []byte {
+		return ClaimExpirationKeyPackPartial(u, nFields)
+	}
+}
+
+func ClaimExpirationKeyPackPartial(k *ClaimExpirationKey, nFields int) []byte {
+	// Limit nFields between 0 and number of fields, we always at least need
+	// the prefix, and we never need to iterate past the number of fields.
+	if nFields > 3 {
+		nFields = 3
+	}
+	if nFields < 0 {
+		nFields = 0
+	}
+
+	// b'>4sLH'
+	prefixLen := 1
+	var n = prefixLen
+	for i := 0; i <= nFields; i++ {
+		switch i {
+		case 1:
+			n += 4
+		case 2:
+			n += 4
+		case 3:
+			n += 2
+		}
+	}
+
+	key := make([]byte, n)
+
+	for i := 0; i <= nFields; i++ {
+		switch i {
+		case 0:
+			copy(key, k.Prefix)
+		case 1:
+			binary.BigEndian.PutUint32(key[prefixLen:], k.Expiration)
+		case 2:
+			binary.BigEndian.PutUint32(key[prefixLen+4:], k.TxNum)
+		case 3:
+			binary.BigEndian.PutUint16(key[prefixLen+8:], k.Position)
+		}
+	}
+
+	return key
+}
+
+func ClaimExpirationKeyUnpack(key []byte) *ClaimExpirationKey {
+	prefixLen := 1
+	return &ClaimExpirationKey{
+		Prefix:     key[:prefixLen],
+		Expiration: binary.BigEndian.Uint32(key[prefixLen:]),
+		TxNum:      binary.BigEndian.Uint32(key[prefixLen+4:]),
+		Position:   binary.BigEndian.Uint16(key[prefixLen+8:]),
+	}
+}
+
+func ClaimExpirationValueUnpack(value []byte) *ClaimExpirationValue {
+	nameLen := binary.BigEndian.Uint16(value[20:])
+	return &ClaimExpirationValue{
+		ClaimHash:      value[:20],
+		NormalizedName: string(value[22 : 22+nameLen]),
+	}
+}
+
 /*
 class ClaimTakeoverKey(typing.NamedTuple):
     normalized_name: str
@@ -1784,7 +1874,7 @@ func UnpackGenericKey(key []byte) (byte, interface{}, error) {
 	case EffectiveAmount:
 		return EffectiveAmount, EffectiveAmountKeyUnpack(key), nil
 	case ClaimExpiration:
-		return 0x0, nil, errors.Base("key unpack function for %v not implemented", firstByte)
+		return ClaimExpiration, ClaimExpirationKeyUnpack(key), nil
 
 	case ClaimTakeover:
 		return ClaimTakeover, ClaimTakeoverKeyUnpack(key), nil
@@ -1849,7 +1939,7 @@ func UnpackGenericValue(key, value []byte) (byte, interface{}, error) {
 	case EffectiveAmount:
 		return EffectiveAmount, EffectiveAmountValueUnpack(value), nil
 	case ClaimExpiration:
-		return 0x0, nil, errors.Base("value unpack not implemented for key %v", key)
+		return ClaimExpiration, ClaimExpirationValueUnpack(value), nil
 
 	case ClaimTakeover:
 		return ClaimTakeover, ClaimTakeoverValueUnpack(value), nil
diff --git a/db/prefixes/prefixes_test.go b/db/prefixes/prefixes_test.go
index 6e2f420..bf47dfa 100644
--- a/db/prefixes/prefixes_test.go
+++ b/db/prefixes/prefixes_test.go
@@ -44,6 +44,90 @@ func testInit(filePath string) (*grocksdb.DB, [][]string, func()) {
 	return db, records, toDefer
 }
 
+func TestClaimExpiration(t *testing.T) {
+
+	filePath := "../../resources/claim_expiration.csv"
+
+	wOpts := grocksdb.NewDefaultWriteOptions()
+	db, records, toDefer := testInit(filePath)
+	defer toDefer()
+	for _, record := range records {
+		key, err := hex.DecodeString(record[0])
+		if err != nil {
+			log.Println(err)
+		}
+		val, err := hex.DecodeString(record[1])
+		if err != nil {
+			log.Println(err)
+		}
+		db.Put(wOpts, key, val)
+	}
+	// test prefix
+	options := dbpkg.NewIterateOptions().WithPrefix([]byte{prefixes.ClaimExpiration}).WithIncludeValue(true)
+	ch := dbpkg.Iter(db, options)
+	var i = 0
+	for kv := range ch {
+		// log.Println(kv.Key)
+		gotKey := kv.Key.(*prefixes.ClaimExpirationKey).PackKey()
+
+		keyPartial1 := prefixes.ClaimExpirationKeyPackPartial(kv.Key.(*prefixes.ClaimExpirationKey), 1)
+		keyPartial2 := prefixes.ClaimExpirationKeyPackPartial(kv.Key.(*prefixes.ClaimExpirationKey), 2)
+		keyPartial3 := prefixes.ClaimExpirationKeyPackPartial(kv.Key.(*prefixes.ClaimExpirationKey), 3)
+
+		// Check pack partial for sanity
+		if !bytes.HasPrefix(gotKey, keyPartial1) {
+			t.Errorf("%+v should be prefix of %+v\n", keyPartial1, gotKey)
+		}
+		if !bytes.HasPrefix(gotKey, keyPartial2) {
+			t.Errorf("%+v should be prefix of %+v\n", keyPartial2, gotKey)
+		}
+		if !bytes.HasPrefix(gotKey, keyPartial3) {
+			t.Errorf("%+v should be prefix of %+v\n", keyPartial3, gotKey)
+		}
+
+		got := kv.Value.(*prefixes.ClaimExpirationValue).PackValue()
+		wantKey, err := hex.DecodeString(records[i][0])
+		if err != nil {
+			log.Println(err)
+		}
+		want, err := hex.DecodeString(records[i][1])
+		if err != nil {
+			log.Println(err)
+		}
+		if !bytes.Equal(gotKey, wantKey) {
+			t.Errorf("gotKey: %+v, wantKey: %+v\n", got, want)
+		}
+		if !bytes.Equal(got, want) {
+			t.Errorf("got: %+v, want: %+v\n", got, want)
+		}
+		i++
+	}
+
+	// Test start / stop
+	start, err := hex.DecodeString(records[0][0])
+	if err != nil {
+		log.Println(err)
+	}
+	stop, err := hex.DecodeString(records[9][0])
+	if err != nil {
+		log.Println(err)
+	}
+	options2 := dbpkg.NewIterateOptions().WithStart(start).WithStop(stop).WithIncludeValue(true)
+	ch2 := dbpkg.Iter(db, options2)
+	i = 0
+	for kv := range ch2 {
+		got := kv.Value.(*prefixes.ClaimExpirationValue).PackValue()
+		want, err := hex.DecodeString(records[i][1])
+		if err != nil {
+			log.Println(err)
+		}
+		if !bytes.Equal(got, want) {
+			t.Errorf("got: %+v, want: %+v\n", got, want)
+		}
+		i++
+	}
+}
+
 func TestClaimTakeover(t *testing.T) {
 
 	filePath := "../../resources/claim_takeover.csv"
diff --git a/main.go b/main.go
index 77c95a9..0a083fd 100644
--- a/main.go
+++ b/main.go
@@ -38,7 +38,7 @@ func main() {
 
 		options := &db.IterOptions{
 			FillCache:    false,
-			Prefix:       []byte{prefixes.ClaimTakeover},
+			Prefix:       []byte{prefixes.ClaimExpiration},
 			Start:        nil,
 			Stop:         nil,
 			IncludeStart: true,
@@ -49,7 +49,7 @@ func main() {
 			RawValue:     true,
 		}
 
-		db.ReadWriteRawN(dbVal, options, "./resources/claim_takeover.csv", 10)
+		db.ReadWriteRawN(dbVal, options, "./resources/claim_expiration.csv", 10)
 
 		return
 	}
diff --git a/resources/claim_expiration.csv b/resources/claim_expiration.csv
new file mode 100644
index 0000000..4cfc623
--- /dev/null
+++ b/resources/claim_expiration.csv
@@ -0,0 +1,10 @@
+4f00222fbd00162aa70000,c78ac4c326cd43cdc0c844b7cea13659449ab3e40015746573742d70686f746f2d7374726173626f757267
+4f002230a700162f600000,ebf95f7fdb89db5467bb1b88ea3b0f0f7ee5ce360003636e63
+4f002230e3001630960000,a6f91a86837ab84a4cf0d2dcbe94704a528cf820000f776f6e646572776f6d616e31393933
+4f002231e8001635e60000,9673cc2a1aac64d7b2742705abfb09fca30d7e0500056d6d61736b
+4f00223246001638a80000,c39342066646dc50f1a9954b41684d157b035dac00036f6e65
+4f00223494001645ef0001,4689c1ccb4420309f93ab98799b28c49fa4d3809000a65617379737472656574
+4f002236df0016529a0000,f1628d66ae52295590b72b9a0b3a3527642a532600137465737470756230332d32312d323031372d32
+4f002236e10016529d0000,a4c61ced261ab571bdb3410ae140bec6c31f14ce00117465737470756230332d32312d32303137
+4f00223774001655960000,2327bcb6d7578a2669e416b5aa185fe14ee8e03e00056569676874
+4f00223a04001664200000,f69099600bdca9b062ba60432dba3c0ca2241167002c686973746f72792d6f662d6672696564726963682d69692d6f662d707275737369612d766f6c756d652d3137