diff --git a/core/services/functions/connector_handler.go b/core/services/functions/connector_handler.go
index a018157a373..8a8710e6ea6 100644
--- a/core/services/functions/connector_handler.go
+++ b/core/services/functions/connector_handler.go
@@ -78,6 +78,13 @@ func (h *functionsConnectorHandler) HandleGatewayMessage(ctx context.Context, ga
 	}
 	if balance, err := h.subscriptions.GetMaxUserBalance(fromAddr); err != nil || balance.Cmp(h.minimumBalance.ToInt()) < 0 {
 		h.lggr.Errorw("user subscription has insufficient balance", "id", gatewayId, "address", fromAddr, "balance", balance, "minBalance", h.minimumBalance)
+		response := functions.SecretsResponseBase{
+			Success:      false,
+			ErrorMessage: "user subscription has insufficient balance",
+		}
+		if err := h.sendResponse(ctx, gatewayId, body, response); err != nil {
+			h.lggr.Errorw("failed to send response to gateway", "id", gatewayId, "error", err)
+		}
 		return
 	}
 
diff --git a/core/services/functions/connector_handler_test.go b/core/services/functions/connector_handler_test.go
index bb3e2acbabd..7bf98d7501d 100644
--- a/core/services/functions/connector_handler_test.go
+++ b/core/services/functions/connector_handler_test.go
@@ -39,7 +39,7 @@ func TestFunctionsConnectorHandler(t *testing.T) {
 	allowlist.On("Close", mock.Anything).Return(nil)
 	subscriptions.On("Start", mock.Anything).Return(nil)
 	subscriptions.On("Close", mock.Anything).Return(nil)
-	handler, err := functions.NewFunctionsConnectorHandler(addr.Hex(), privateKey, storage, allowlist, rateLimiter, subscriptions, *assets.NewLinkFromJuels(0), logger)
+	handler, err := functions.NewFunctionsConnectorHandler(addr.Hex(), privateKey, storage, allowlist, rateLimiter, subscriptions, *assets.NewLinkFromJuels(100), logger)
 	require.NoError(t, err)
 
 	handler.SetConnector(connector)
@@ -78,7 +78,7 @@ func TestFunctionsConnectorHandler(t *testing.T) {
 			}
 			storage.On("List", ctx, addr).Return(snapshot, nil).Once()
 			allowlist.On("Allow", addr).Return(true).Once()
-			subscriptions.On("GetMaxUserBalance", mock.Anything).Return(big.NewInt(100), nil)
+			subscriptions.On("GetMaxUserBalance", mock.Anything).Return(big.NewInt(100), nil).Once()
 			connector.On("SendToGateway", ctx, "gw1", mock.Anything).Run(func(args mock.Arguments) {
 				msg, ok := args[2].(*api.Message)
 				require.True(t, ok)
@@ -91,6 +91,7 @@ func TestFunctionsConnectorHandler(t *testing.T) {
 			t.Run("orm error", func(t *testing.T) {
 				storage.On("List", ctx, addr).Return(nil, errors.New("boom")).Once()
 				allowlist.On("Allow", addr).Return(true).Once()
+				subscriptions.On("GetMaxUserBalance", mock.Anything).Return(big.NewInt(100), nil).Once()
 				connector.On("SendToGateway", ctx, "gw1", mock.Anything).Run(func(args mock.Arguments) {
 					msg, ok := args[2].(*api.Message)
 					require.True(t, ok)
@@ -135,7 +136,7 @@ func TestFunctionsConnectorHandler(t *testing.T) {
 
 			storage.On("Put", ctx, &key, &record, signature).Return(nil).Once()
 			allowlist.On("Allow", addr).Return(true).Once()
-			subscriptions.On("GetMaxUserBalance", mock.Anything).Return(big.NewInt(100), nil)
+			subscriptions.On("GetMaxUserBalance", mock.Anything).Return(big.NewInt(100), nil).Once()
 			connector.On("SendToGateway", ctx, "gw1", mock.Anything).Run(func(args mock.Arguments) {
 				msg, ok := args[2].(*api.Message)
 				require.True(t, ok)
@@ -148,6 +149,7 @@ func TestFunctionsConnectorHandler(t *testing.T) {
 			t.Run("orm error", func(t *testing.T) {
 				storage.On("Put", ctx, mock.Anything, mock.Anything, mock.Anything).Return(errors.New("boom")).Once()
 				allowlist.On("Allow", addr).Return(true).Once()
+				subscriptions.On("GetMaxUserBalance", mock.Anything).Return(big.NewInt(100), nil).Once()
 				connector.On("SendToGateway", ctx, "gw1", mock.Anything).Run(func(args mock.Arguments) {
 					msg, ok := args[2].(*api.Message)
 					require.True(t, ok)
@@ -163,6 +165,7 @@ func TestFunctionsConnectorHandler(t *testing.T) {
 				require.NoError(t, msg.Sign(privateKey))
 				storage.On("Put", ctx, mock.Anything, mock.Anything, mock.Anything).Return(s4.ErrWrongSignature).Once()
 				allowlist.On("Allow", addr).Return(true).Once()
+				subscriptions.On("GetMaxUserBalance", mock.Anything).Return(big.NewInt(100), nil).Once()
 				connector.On("SendToGateway", ctx, "gw1", mock.Anything).Run(func(args mock.Arguments) {
 					msg, ok := args[2].(*api.Message)
 					require.True(t, ok)
@@ -177,6 +180,7 @@ func TestFunctionsConnectorHandler(t *testing.T) {
 				msg.Body.Payload = json.RawMessage(`{sdfgdfgoscsicosd:sdf:::sdf ::; xx}`)
 				require.NoError(t, msg.Sign(privateKey))
 				allowlist.On("Allow", addr).Return(true).Once()
+				subscriptions.On("GetMaxUserBalance", mock.Anything).Return(big.NewInt(100), nil).Once()
 				connector.On("SendToGateway", ctx, "gw1", mock.Anything).Run(func(args mock.Arguments) {
 					msg, ok := args[2].(*api.Message)
 					require.True(t, ok)
@@ -186,6 +190,19 @@ func TestFunctionsConnectorHandler(t *testing.T) {
 
 				handler.HandleGatewayMessage(ctx, "gw1", &msg)
 			})
+
+			t.Run("insufficient balance", func(t *testing.T) {
+				allowlist.On("Allow", addr).Return(true).Once()
+				subscriptions.On("GetMaxUserBalance", mock.Anything).Return(big.NewInt(0), nil).Once()
+				connector.On("SendToGateway", ctx, "gw1", mock.Anything).Run(func(args mock.Arguments) {
+					msg, ok := args[2].(*api.Message)
+					require.True(t, ok)
+					require.Equal(t, `{"success":false,"error_message":"user subscription has insufficient balance"}`, string(msg.Body.Payload))
+
+				}).Return(nil).Once()
+
+				handler.HandleGatewayMessage(ctx, "gw1", &msg)
+			})
 		})
 
 		t.Run("unsupported method", func(t *testing.T) {
@@ -201,6 +218,7 @@ func TestFunctionsConnectorHandler(t *testing.T) {
 			require.NoError(t, msg.Sign(privateKey))
 
 			allowlist.On("Allow", addr).Return(true).Once()
+			subscriptions.On("GetMaxUserBalance", mock.Anything).Return(big.NewInt(100), nil).Once()
 			handler.HandleGatewayMessage(testutils.Context(t), "gw1", &msg)
 		})
 	})