diff --git a/services/payments/src/simcore_service_payments/core/errors.py b/services/payments/src/simcore_service_payments/core/errors.py
index 748290c98a6a..186d37108c8e 100644
--- a/services/payments/src/simcore_service_payments/core/errors.py
+++ b/services/payments/src/simcore_service_payments/core/errors.py
@@ -2,8 +2,10 @@
 
 
 class BaseServiceError(PydanticErrorMixin, ValueError):
-    # TODO: error.code = __class__.__name__ and being able to de/serialize via rpc
-    ...
+    @classmethod
+    def get_full_class_name(cls) -> str:
+        # Can be used as unique code identifier
+        return f"{cls.__module__}.{cls.__name__}"
 
 
 class PaymentsError(BaseServiceError):
diff --git a/services/payments/tests/unit/test_rpc_payments.py b/services/payments/tests/unit/test_rpc_payments.py
index fcf9e3b4e3dc..c69bb57506fa 100644
--- a/services/payments/tests/unit/test_rpc_payments.py
+++ b/services/payments/tests/unit/test_rpc_payments.py
@@ -6,7 +6,6 @@
 
 from typing import Any
 
-import httpx
 import pytest
 from faker import Faker
 from fastapi import FastAPI
@@ -70,7 +69,7 @@ def init_payment_kwargs(faker: Faker) -> dict[str, Any]:
 
 
 @pytest.fixture
-def _disable_startup(mocker: MockerFixture):
+def _with_disabled_payments_gateway_startup(mocker: MockerFixture):
     mocker.patch(
         "simcore_service_payments.services.payments_gateway._create_start_policy",
         return_value=lambda: print("on-startup"),
@@ -79,7 +78,7 @@ def _disable_startup(mocker: MockerFixture):
 
 async def test_rpc_init_payment_fail(
     is_pdb_enabled: bool,
-    _disable_startup,
+    _with_disabled_payments_gateway_startup: None,
     app: FastAPI,
     rpc_client: RabbitMQRPCClient,
     init_payment_kwargs: dict[str, Any],
@@ -95,10 +94,11 @@ async def test_rpc_init_payment_fail(
             timeout_s=None if is_pdb_enabled else 5,
         )
 
-    exc: RPCServerError = exc_info.value
-    assert exc.exc_type == f"{httpx.ConnectError}"
-    assert exc.method_name == "init_payment"
-    assert exc.msg
+    error = exc_info.value
+    assert isinstance(error, RPCServerError)
+    assert error.exc_type == "httpx.ConnectError"
+    assert error.method_name == "init_payment"
+    assert error.msg
 
 
 async def test_webserver_one_time_payment_workflow(
@@ -139,8 +139,9 @@ async def test_webserver_one_time_payment_workflow(
 
 async def test_cancel_invalid_payment_id(
     is_pdb_enabled: bool,
-    rpc_client: RabbitMQRPCClient,
     mock_payments_gateway_service_or_none: MockRouter | None,
+    app: FastAPI,
+    rpc_client: RabbitMQRPCClient,
     init_payment_kwargs: dict[str, Any],
     faker: Faker,
     payments_clean_db: None,
@@ -159,7 +160,7 @@ async def test_cancel_invalid_payment_id(
     error = exc_info.value
 
     assert isinstance(error, RPCServerError)
-    assert error.exc_type == f"{PaymentNotFoundError}"
+    assert error.exc_type == PaymentNotFoundError.get_full_class_name()
     assert error.method_name == "cancel_payment"
     assert error.msg == PaymentNotFoundError.msg_template.format(
         payment_id=invalid_payment_id