diff --git a/pkg/owner/id.go b/pkg/owner/id.go
index 08971e8..49acb2c 100644
--- a/pkg/owner/id.go
+++ b/pkg/owner/id.go
@@ -71,3 +71,35 @@ func (id *ID) Parse(s string) error {
 
 	return nil
 }
+
+// Marshal marshals ID into a protobuf binary form.
+//
+// Buffer is allocated when the argument is empty.
+// Otherwise, the first buffer is used.
+func (id *ID) Marshal(b ...[]byte) ([]byte, error) {
+	var buf []byte
+	if len(b) > 0 {
+		buf = b[0]
+	}
+
+	return (*refs.OwnerID)(id).
+		StableMarshal(buf)
+}
+
+// Unmarshal unmarshals protobuf binary representation of ID.
+func (id *ID) Unmarshal(data []byte) error {
+	return (*refs.OwnerID)(id).
+		Unmarshal(data)
+}
+
+// MarshalJSON encodes ID to protobuf JSON format.
+func (id *ID) MarshalJSON() ([]byte, error) {
+	return (*refs.OwnerID)(id).
+		MarshalJSON()
+}
+
+// UnmarshalJSON decodes ID from protobuf JSON format.
+func (id *ID) UnmarshalJSON(data []byte) error {
+	return (*refs.OwnerID)(id).
+		UnmarshalJSON(data)
+}
diff --git a/pkg/owner/id_test.go b/pkg/owner/id_test.go
index a36324f..8d867df 100644
--- a/pkg/owner/id_test.go
+++ b/pkg/owner/id_test.go
@@ -10,7 +10,7 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func TestIDV2(t *testing.T) {
+func randID(t *testing.T) *ID {
 	id := NewID()
 
 	wallet := new(NEO3Wallet)
@@ -20,9 +20,15 @@ func TestIDV2(t *testing.T) {
 
 	id.SetNeo3Wallet(wallet)
 
+	return id
+}
+
+func TestIDV2(t *testing.T) {
+	id := randID(t)
+
 	idV2 := id.ToV2()
 
-	require.Equal(t, wallet.Bytes(), idV2.GetValue())
+	require.Equal(t, id, NewIDFromV2(idV2))
 }
 
 func TestNewIDFromNeo3Wallet(t *testing.T) {
@@ -63,3 +69,27 @@ func TestID_Parse(t *testing.T) {
 		}
 	})
 }
+
+func TestIDEncoding(t *testing.T) {
+	id := randID(t)
+
+	t.Run("binary", func(t *testing.T) {
+		data, err := id.Marshal()
+		require.NoError(t, err)
+
+		id2 := NewID()
+		require.NoError(t, id2.Unmarshal(data))
+
+		require.Equal(t, id, id2)
+	})
+
+	t.Run("json", func(t *testing.T) {
+		data, err := id.MarshalJSON()
+		require.NoError(t, err)
+
+		a2 := NewID()
+		require.NoError(t, a2.UnmarshalJSON(data))
+
+		require.Equal(t, id, a2)
+	})
+}
diff --git a/v2/refs/json.go b/v2/refs/json.go
index d2fd4ed..e552ae1 100644
--- a/v2/refs/json.go
+++ b/v2/refs/json.go
@@ -64,3 +64,23 @@ func (c *ContainerID) UnmarshalJSON(data []byte) error {
 
 	return nil
 }
+
+func (o *OwnerID) MarshalJSON() ([]byte, error) {
+	return protojson.MarshalOptions{
+		EmitUnpopulated: true,
+	}.Marshal(
+		OwnerIDToGRPCMessage(o),
+	)
+}
+
+func (o *OwnerID) UnmarshalJSON(data []byte) error {
+	msg := new(refs.OwnerID)
+
+	if err := protojson.Unmarshal(data, msg); err != nil {
+		return err
+	}
+
+	*o = *OwnerIDFromGRPCMessage(msg)
+
+	return nil
+}
diff --git a/v2/refs/json_test.go b/v2/refs/json_test.go
index b56b1d0..c5684e9 100644
--- a/v2/refs/json_test.go
+++ b/v2/refs/json_test.go
@@ -44,3 +44,16 @@ func TestContainerIDJSON(t *testing.T) {
 
 	require.Equal(t, cid, cid2)
 }
+
+func TestOwnerIDJSON(t *testing.T) {
+	o := new(refs.OwnerID)
+	o.SetValue([]byte{1})
+
+	data, err := o.MarshalJSON()
+	require.NoError(t, err)
+
+	o2 := new(refs.OwnerID)
+	require.NoError(t, o2.UnmarshalJSON(data))
+
+	require.Equal(t, o, o2)
+}
diff --git a/v2/refs/marshal.go b/v2/refs/marshal.go
index 37b950d..0a2484a 100644
--- a/v2/refs/marshal.go
+++ b/v2/refs/marshal.go
@@ -51,6 +51,17 @@ func (o *OwnerID) StableSize() int {
 	return proto.BytesSize(ownerIDValField, o.val)
 }
 
+func (o *OwnerID) Unmarshal(data []byte) error {
+	m := new(refs.OwnerID)
+	if err := goproto.Unmarshal(data, m); err != nil {
+		return err
+	}
+
+	*o = *OwnerIDFromGRPCMessage(m)
+
+	return nil
+}
+
 func (c *ContainerID) StableMarshal(buf []byte) ([]byte, error) {
 	if c == nil {
 		return []byte{}, nil
diff --git a/v2/refs/marshal_test.go b/v2/refs/marshal_test.go
index d0eb75f..4c12ea2 100644
--- a/v2/refs/marshal_test.go
+++ b/v2/refs/marshal_test.go
@@ -11,7 +11,6 @@ import (
 
 func TestOwnerID_StableMarshal(t *testing.T) {
 	ownerFrom := new(refs.OwnerID)
-	ownerTransport := new(grpc.OwnerID)
 
 	t.Run("non empty", func(t *testing.T) {
 		ownerFrom.SetValue([]byte("Owner ID"))
@@ -19,10 +18,9 @@ func TestOwnerID_StableMarshal(t *testing.T) {
 		wire, err := ownerFrom.StableMarshal(nil)
 		require.NoError(t, err)
 
-		err = goproto.Unmarshal(wire, ownerTransport)
-		require.NoError(t, err)
+		ownerTo := new(refs.OwnerID)
+		require.NoError(t, ownerTo.Unmarshal(wire))
 
-		ownerTo := refs.OwnerIDFromGRPCMessage(ownerTransport)
 		require.Equal(t, ownerFrom, ownerTo)
 	})
 }