diff --git a/types/transaction.go b/types/transaction.go
index b7d4ba8..d8308ac 100644
--- a/types/transaction.go
+++ b/types/transaction.go
@@ -115,6 +115,12 @@ type TxInputGenesis struct {
 // InputType returns the wire variant tag for genesis inputs.
 func (t TxInputGenesis) InputType() uint8 { return InputTypeGenesis }
 
+// TxOutTarget is the interface implemented by all output target types
+// within a TxOutputBare. Each target variant has a unique wire tag.
+type TxOutTarget interface {
+	TargetType() uint8
+}
+
 // TxOutToKey is the txout_to_key target variant. On the wire it is
 // serialised as a 33-byte packed blob: 32-byte public key + 1-byte mix_attr.
 type TxOutToKey struct {
@@ -122,6 +128,9 @@ type TxOutToKey struct {
 	MixAttr uint8
 }
 
+// TargetType returns the wire variant tag for to_key targets.
+func (t TxOutToKey) TargetType() uint8 { return TargetTypeToKey }
+
 // TxOutRef is one element of a txin_to_key key_offsets vector.
 // Each element is a variant: either a uint64 global index or a ref_by_id.
 type TxOutRef struct {
diff --git a/types/transaction_test.go b/types/transaction_test.go
new file mode 100644
index 0000000..e7451b1
--- /dev/null
+++ b/types/transaction_test.go
@@ -0,0 +1,15 @@
+// Copyright (c) 2017-2026 Lethean (https://lt.hn)
+//
+// Licensed under the European Union Public Licence (EUPL) version 1.2.
+// SPDX-License-Identifier: EUPL-1.2
+
+package types
+
+import "testing"
+
+func TestTxOutToKey_TargetType_Good(t *testing.T) {
+	var target TxOutTarget = TxOutToKey{Key: PublicKey{1}, MixAttr: 0}
+	if target.TargetType() != TargetTypeToKey {
+		t.Errorf("TargetType: got %d, want %d", target.TargetType(), TargetTypeToKey)
+	}
+}