diff --git a/domains/noto/internal/msgs/en_errors.go b/domains/noto/internal/msgs/en_errors.go
index 137d1615f..18572b924 100644
--- a/domains/noto/internal/msgs/en_errors.go
+++ b/domains/noto/internal/msgs/en_errors.go
@@ -59,4 +59,5 @@ var (
 	MsgSignatureDoesNotMatch       = ffe("PD200017", "Signature for '%s' did not match: expected=%s actual=%s")
 	MsgStateWrongOwner             = ffe("PD200018", "State '%s' is not owned by '%s'")
 	MsgUnrecognizedEndorsement     = ffe("PD200019", "Unrecognized endorsement request: %s")
+	MsgDuplicateStateInList        = ffe("PD200020", "Duplicate state in list %s[%d] (%s)")
 )
diff --git a/domains/noto/internal/noto/e2e_noto_test.go b/domains/noto/internal/noto/e2e_noto_test.go
index 8e2424d87..e09cf97c0 100644
--- a/domains/noto/internal/noto/e2e_noto_test.go
+++ b/domains/noto/internal/noto/e2e_noto_test.go
@@ -190,6 +190,10 @@ func TestNoto(t *testing.T) {
 	assert.ErrorContains(t, rpcerr.Error(), "PD200009")
 	assert.True(t, boolResult)
 
+	coins, err = noto.FindCoins(ctx, "{}")
+	require.NoError(t, err)
+	require.Len(t, coins, 1)
+
 	log.L(ctx).Infof("Transfer 150 from notary (should fail)")
 	rpcerr = rpc.CallRPC(ctx, &boolResult, "testbed_invoke", &tktypes.PrivateContractInvoke{
 		From:     notaryName,
@@ -203,6 +207,10 @@ func TestNoto(t *testing.T) {
 	require.NotNil(t, rpcerr)
 	assert.ErrorContains(t, rpcerr.Error(), "PD200005")
 
+	coins, err = noto.FindCoins(ctx, "{}")
+	require.NoError(t, err)
+	require.Len(t, coins, 1)
+
 	log.L(ctx).Infof("Transfer 50 from notary to recipient1")
 	rpcerr = rpc.CallRPC(ctx, &boolResult, "testbed_invoke", &tktypes.PrivateContractInvoke{
 		From:     notaryName,
diff --git a/domains/noto/internal/noto/noto.go b/domains/noto/internal/noto/noto.go
index bd2d2f278..ae9610eb0 100644
--- a/domains/noto/internal/noto/noto.go
+++ b/domains/noto/internal/noto/noto.go
@@ -289,19 +289,24 @@ func (n *Noto) recoverSignature(ctx context.Context, payload ethtypes.HexBytes0x
 
 func (n *Noto) parseCoinList(ctx context.Context, label string, states []*pb.EndorsableState) ([]*types.NotoCoin, []*pb.StateRef, *big.Int, error) {
 	var err error
+	statesUsed := make(map[string]bool)
 	coins := make([]*types.NotoCoin, len(states))
 	refs := make([]*pb.StateRef, len(states))
 	total := big.NewInt(0)
-	for i, input := range states {
-		if input.SchemaId != n.coinSchema.Id {
-			return nil, nil, nil, i18n.NewError(ctx, msgs.MsgUnknownSchema, input.SchemaId)
+	for i, state := range states {
+		if state.SchemaId != n.coinSchema.Id {
+			return nil, nil, nil, i18n.NewError(ctx, msgs.MsgUnknownSchema, state.SchemaId)
+		}
+		if statesUsed[state.Id] {
+			return nil, nil, nil, i18n.NewError(ctx, msgs.MsgDuplicateStateInList, label, i, state.Id)
 		}
-		if coins[i], err = n.unmarshalCoin(input.StateDataJson); err != nil {
-			return nil, nil, nil, i18n.NewError(ctx, msgs.MsgInvalidListInput, label, i, input.Id, err)
+		statesUsed[state.Id] = true
+		if coins[i], err = n.unmarshalCoin(state.StateDataJson); err != nil {
+			return nil, nil, nil, i18n.NewError(ctx, msgs.MsgInvalidListInput, label, i, state.Id, err)
 		}
 		refs[i] = &pb.StateRef{
-			SchemaId: input.SchemaId,
-			Id:       input.Id,
+			SchemaId: state.SchemaId,
+			Id:       state.Id,
 		}
 		total = total.Add(total, coins[i].Amount.BigInt())
 	}
diff --git a/domains/noto/internal/noto/states.go b/domains/noto/internal/noto/states.go
index 483d0c6b7..37bf37ec2 100644
--- a/domains/noto/internal/noto/states.go
+++ b/domains/noto/internal/noto/states.go
@@ -89,6 +89,7 @@ func (n *Noto) prepareInputs(ctx context.Context, owner ethtypes.Address0xHex, a
 	stateRefs := []*pb.StateRef{}
 	coins := []*types.NotoCoin{}
 	for {
+		// TODO: make this configurable
 		queryBuilder := query.NewQueryBuilder().
 			Limit(10).
 			Sort(".created").