diff --git a/pkg/network/payload/extensible.go b/pkg/network/payload/extensible.go
new file mode 100644
index 000000000..7df9ffd33
--- /dev/null
+++ b/pkg/network/payload/extensible.go
@@ -0,0 +1,126 @@
+package payload
+
+import (
+	"errors"
+	"math"
+
+	"github.com/nspcc-dev/neo-go/pkg/config/netmode"
+	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
+	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
+	"github.com/nspcc-dev/neo-go/pkg/io"
+	"github.com/nspcc-dev/neo-go/pkg/util"
+)
+
+const (
+	maxExtensibleCategorySize = 32
+	maxExtensibleDataSize     = math.MaxUint16
+)
+
+// Extensible represents payload containing arbitrary data.
+type Extensible struct {
+	// Network represents network magic.
+	Network netmode.Magic
+	// Category is payload type.
+	Category string
+	// ValidBlockStart is starting height for payload to be valid.
+	ValidBlockStart uint32
+	// ValidBlockEnd is height after which payload becomes invalid.
+	ValidBlockEnd uint32
+	// Sender is payload sender or signer.
+	Sender util.Uint160
+	// Data is custom payload data.
+	Data []byte
+	// Witness is payload witness.
+	Witness transaction.Witness
+
+	hash       util.Uint256
+	signedHash util.Uint256
+	signedpart []byte
+}
+
+var errInvalidPadding = errors.New("invalid padding")
+
+// NewExtensible creates new extensible payload.
+func NewExtensible(network netmode.Magic) *Extensible {
+	return &Extensible{Network: network}
+}
+
+func (e *Extensible) encodeBinaryUnsigned(w *io.BinWriter) {
+	w.WriteString(e.Category)
+	w.WriteU32LE(e.ValidBlockStart)
+	w.WriteU32LE(e.ValidBlockEnd)
+	w.WriteBytes(e.Sender[:])
+	w.WriteVarBytes(e.Data)
+}
+
+// EncodeBinary implements io.Serializable.
+func (e *Extensible) EncodeBinary(w *io.BinWriter) {
+	e.encodeBinaryUnsigned(w)
+	w.WriteB(1)
+	e.Witness.EncodeBinary(w)
+}
+
+func (e *Extensible) decodeBinaryUnsigned(r *io.BinReader) {
+	e.Category = r.ReadString(maxExtensibleCategorySize)
+	e.ValidBlockStart = r.ReadU32LE()
+	e.ValidBlockEnd = r.ReadU32LE()
+	r.ReadBytes(e.Sender[:])
+	e.Data = r.ReadVarBytes(maxExtensibleDataSize)
+}
+
+// DecodeBinary implements io.Serializable.
+func (e *Extensible) DecodeBinary(r *io.BinReader) {
+	e.decodeBinaryUnsigned(r)
+	if r.ReadB() != 1 {
+		if r.Err != nil {
+			return
+		}
+		r.Err = errInvalidPadding
+		return
+	}
+	e.Witness.DecodeBinary(r)
+}
+
+// GetSignedPart implements crypto.Verifiable.
+func (e *Extensible) GetSignedPart() []byte {
+	if e.signedpart == nil {
+		e.updateSignedPart()
+	}
+	return e.signedpart
+}
+
+// GetSignedHash implements crypto.Verifiable.
+func (e *Extensible) GetSignedHash() util.Uint256 {
+	if e.signedHash.Equals(util.Uint256{}) {
+		e.createHash()
+	}
+	return e.signedHash
+}
+
+// Hash returns payload hash.
+func (e *Extensible) Hash() util.Uint256 {
+	if e.hash.Equals(util.Uint256{}) {
+		e.createHash()
+	}
+	return e.hash
+}
+
+// createHash creates hashes of the payload.
+func (e *Extensible) createHash() {
+	b := e.GetSignedPart()
+	e.updateHashes(b)
+}
+
+// updateHashes updates hashes based on the given buffer which should
+// be a signable data slice.
+func (e *Extensible) updateHashes(b []byte) {
+	e.signedHash = hash.Sha256(b)
+	e.hash = hash.Sha256(e.signedHash.BytesBE())
+}
+
+// updateSignedPart updates serialized message if needed.
+func (e *Extensible) updateSignedPart() {
+	w := io.NewBufBinWriter()
+	e.encodeBinaryUnsigned(w.BinWriter)
+	e.signedpart = w.Bytes()
+}
diff --git a/pkg/network/payload/extensible_test.go b/pkg/network/payload/extensible_test.go
new file mode 100644
index 000000000..846ed676c
--- /dev/null
+++ b/pkg/network/payload/extensible_test.go
@@ -0,0 +1,71 @@
+package payload
+
+import (
+	"errors"
+	gio "io"
+	"testing"
+
+	"github.com/nspcc-dev/neo-go/internal/random"
+	"github.com/nspcc-dev/neo-go/internal/testserdes"
+	"github.com/nspcc-dev/neo-go/pkg/config/netmode"
+	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
+	"github.com/nspcc-dev/neo-go/pkg/io"
+	"github.com/stretchr/testify/require"
+)
+
+func TestExtensible_Serializable(t *testing.T) {
+	expected := &Extensible{
+		Category:        "test",
+		ValidBlockStart: 12,
+		ValidBlockEnd:   1234,
+		Sender:          random.Uint160(),
+		Data:            random.Bytes(4),
+		Witness: transaction.Witness{
+			InvocationScript:   random.Bytes(3),
+			VerificationScript: random.Bytes(3),
+		},
+	}
+
+	testserdes.EncodeDecodeBinary(t, expected, new(Extensible))
+
+	t.Run("invalid", func(t *testing.T) {
+		w := io.NewBufBinWriter()
+		expected.encodeBinaryUnsigned(w.BinWriter)
+		unsigned := w.Bytes()
+
+		t.Run("unexpected EOF", func(t *testing.T) {
+			err := testserdes.DecodeBinary(unsigned, new(Extensible))
+			require.True(t, errors.Is(err, gio.EOF))
+		})
+		t.Run("invalid padding", func(t *testing.T) {
+			err := testserdes.DecodeBinary(append(unsigned, 42), new(Extensible))
+			require.True(t, errors.Is(err, errInvalidPadding))
+		})
+	})
+}
+
+func TestExtensible_Hashes(t *testing.T) {
+	getExtensiblePair := func() (*Extensible, *Extensible) {
+		p1 := NewExtensible(netmode.UnitTestNet)
+		p1.Data = []byte{1, 2, 3}
+		p2 := NewExtensible(netmode.UnitTestNet)
+		p2.Data = []byte{3, 2, 1}
+		return p1, p2
+	}
+
+	t.Run("GetSignedPart", func(t *testing.T) {
+		p1, p2 := getExtensiblePair()
+		require.NotEqual(t, p1.GetSignedPart(), p2.GetSignedPart())
+		require.NotEqual(t, p1.GetSignedPart(), p2.GetSignedPart())
+	})
+	t.Run("GetSignedHash", func(t *testing.T) {
+		p1, p2 := getExtensiblePair()
+		require.NotEqual(t, p1.GetSignedHash(), p2.GetSignedHash())
+		require.NotEqual(t, p1.GetSignedHash(), p2.GetSignedHash())
+	})
+	t.Run("Hash", func(t *testing.T) {
+		p1, p2 := getExtensiblePair()
+		require.NotEqual(t, p1.Hash(), p2.Hash())
+		require.NotEqual(t, p1.Hash(), p2.Hash())
+	})
+}