diff --git a/packages/models-library/src/models_library/users.py b/packages/models-library/src/models_library/users.py
index 31ca948a1b8..a28add967a6 100644
--- a/packages/models-library/src/models_library/users.py
+++ b/packages/models-library/src/models_library/users.py
@@ -22,7 +22,7 @@ class UserBillingDetails(BaseModel):
     address: str | None
     city: str | None
     state: str | None = Field(description="State, province, canton, ...")
-    country: str
+    country: str  # Required for taxes
     postal_code: str | None
     phone: str | None
 
diff --git a/services/web/server/src/simcore_service_webserver/payments/_onetime_api.py b/services/web/server/src/simcore_service_webserver/payments/_onetime_api.py
index f1c9f9df733..f54f48403bb 100644
--- a/services/web/server/src/simcore_service_webserver/payments/_onetime_api.py
+++ b/services/web/server/src/simcore_service_webserver/payments/_onetime_api.py
@@ -279,6 +279,7 @@ async def init_creation_of_wallet_payment(
     Raises:
         UserNotFoundError
         WalletAccessForbiddenError
+        BillingDetailsNotFoundError
     """
 
     # wallet: check permissions
@@ -293,6 +294,7 @@ async def init_creation_of_wallet_payment(
     # user info
     user = await get_user_display_and_id_names(app, user_id=user_id)
     user_invoice_address = await get_user_invoice_address(app, user_id=user_id)
+
     # stripe info
     product_stripe_info = await get_product_stripe_info(app, product_name=product_name)
 
diff --git a/services/web/server/src/simcore_service_webserver/products/_model.py b/services/web/server/src/simcore_service_webserver/products/_model.py
index de3955652a3..cccd7707008 100644
--- a/services/web/server/src/simcore_service_webserver/products/_model.py
+++ b/services/web/server/src/simcore_service_webserver/products/_model.py
@@ -111,7 +111,7 @@ class Product(BaseModel):
 
     @validator("*", pre=True)
     @classmethod
-    def parse_empty_string_as_null(cls, v):
+    def _parse_empty_string_as_null(cls, v):
         """Safe measure: database entries are sometimes left blank instead of null"""
         if isinstance(v, str) and len(v.strip()) == 0:
             return None
@@ -119,12 +119,21 @@ def parse_empty_string_as_null(cls, v):
 
     @validator("name", pre=True, always=True)
     @classmethod
-    def validate_name(cls, v):
+    def _validate_name(cls, v):
         if v not in FRONTEND_APPS_AVAILABLE:
             msg = f"{v} is not in available front-end apps {FRONTEND_APPS_AVAILABLE}"
             raise ValueError(msg)
         return v
 
+    @validator("host_regex", pre=True)
+    @classmethod
+    def _strip_whitespaces(cls, v):
+        if v and isinstance(v, str):
+            # Prevents unintended leading & trailing spaces when added
+            # manually in the database
+            return v.strip()
+        return v
+
     @property
     def twilio_alpha_numeric_sender_id(self) -> str:
         return self.short_name or self.display_name.replace(string.punctuation, "")[:11]
@@ -132,9 +141,10 @@ def twilio_alpha_numeric_sender_id(self) -> str:
     class Config:
         alias_generator = snake_to_camel  # to export
         allow_population_by_field_name = True
+        anystr_strip_whitespace = True
+        extra = Extra.ignore
         frozen = True  # read-only
         orm_mode = True
-        extra = Extra.ignore
         schema_extra: ClassVar[dict[str, Any]] = {
             "examples": [
                 {
diff --git a/services/web/server/src/simcore_service_webserver/users/_db.py b/services/web/server/src/simcore_service_webserver/users/_db.py
index 100575cd522..f7d8769f963 100644
--- a/services/web/server/src/simcore_service_webserver/users/_db.py
+++ b/services/web/server/src/simcore_service_webserver/users/_db.py
@@ -21,6 +21,7 @@
 
 from ..db.models import user_to_groups
 from ..db.plugin import get_database_engine
+from .exceptions import BillingDetailsNotFoundError
 from .schemas import Permission
 
 _ALL = None
@@ -203,9 +204,12 @@ async def new_user_details(
 async def get_user_billing_details(
     engine: Engine, user_id: UserID
 ) -> UserBillingDetails:
+    """
+    Raises:
+        BillingDetailsNotFoundError
+    """
     async with engine.acquire() as conn:
         user_billing_details = await UsersRepo.get_billing_details(conn, user_id)
         if not user_billing_details:
-            msg = f"Missing biling details for user {user_id}"
-            raise ValueError(msg)
+            raise BillingDetailsNotFoundError(user_id=user_id)
         return UserBillingDetails.from_orm(user_billing_details)
diff --git a/services/web/server/src/simcore_service_webserver/users/exceptions.py b/services/web/server/src/simcore_service_webserver/users/exceptions.py
index 08e1432ece0..13b14ee0240 100644
--- a/services/web/server/src/simcore_service_webserver/users/exceptions.py
+++ b/services/web/server/src/simcore_service_webserver/users/exceptions.py
@@ -45,3 +45,8 @@ class AlreadyPreRegisteredError(UsersBaseError):
     msg_template = (
         "Found {num_found} matches for '{email}'. Cannot pre-register existing user"
     )
+
+
+class BillingDetailsNotFoundError(UsersBaseError):
+    # NOTE: this is for internal log and should not be transmitted to the final user
+    msg_template = "Billing details are missing for user_id={user_id}. TIP: Check whether this user is pre-registered"
diff --git a/services/web/server/src/simcore_service_webserver/wallets/_constants.py b/services/web/server/src/simcore_service_webserver/wallets/_constants.py
index a8354070f93..eab6335e3df 100644
--- a/services/web/server/src/simcore_service_webserver/wallets/_constants.py
+++ b/services/web/server/src/simcore_service_webserver/wallets/_constants.py
@@ -3,3 +3,8 @@
 MSG_PRICE_NOT_DEFINED_ERROR: Final[
     str
 ] = "No payments are accepted until this product has a price"
+
+MSG_BILLING_DETAILS_NOT_DEFINED_ERROR: Final[str] = (
+    "Payments cannot be processed: Required billing details (e.g. country for tax) are missing from your account."
+    "Please contact support to resolve this configuration issue."
+)
diff --git a/services/web/server/src/simcore_service_webserver/wallets/_handlers.py b/services/web/server/src/simcore_service_webserver/wallets/_handlers.py
index 0b43bbea59a..e7c67919f10 100644
--- a/services/web/server/src/simcore_service_webserver/wallets/_handlers.py
+++ b/services/web/server/src/simcore_service_webserver/wallets/_handlers.py
@@ -18,6 +18,8 @@
     parse_request_path_parameters_as,
 )
 from servicelib.aiohttp.typing_extension import Handler
+from servicelib.error_codes import create_error_code
+from servicelib.logging_utils import LogExtra, get_log_record_extra
 from servicelib.request_keys import RQT_USERID_KEY
 
 from .._constants import RQ_PRODUCT_KEY
@@ -36,10 +38,16 @@
 )
 from ..products.errors import BelowMinimumPaymentError, ProductPriceNotDefinedError
 from ..security.decorators import permission_required
-from ..users.exceptions import UserDefaultWalletNotFoundError
+from ..users.exceptions import (
+    BillingDetailsNotFoundError,
+    UserDefaultWalletNotFoundError,
+)
 from ..utils_aiohttp import envelope_json_response
 from . import _api
-from ._constants import MSG_PRICE_NOT_DEFINED_ERROR
+from ._constants import (
+    MSG_BILLING_DETAILS_NOT_DEFINED_ERROR,
+    MSG_PRICE_NOT_DEFINED_ERROR,
+)
 from .errors import WalletAccessForbiddenError, WalletNotFoundError
 
 _logger = logging.getLogger(__name__)
@@ -80,6 +88,20 @@ async def wrapper(request: web.Request) -> web.StreamResponse:
         except ProductPriceNotDefinedError as exc:
             raise web.HTTPConflict(reason=MSG_PRICE_NOT_DEFINED_ERROR) from exc
 
+        except BillingDetailsNotFoundError as exc:
+            error_code = create_error_code(exc)
+            log_extra: LogExtra = {}
+            if user_id := getattr(exc, "user_id", None):
+                log_extra = get_log_record_extra(user_id=user_id) or {}
+
+            log_msg = f"{exc} [{error_code}]"
+            _logger.exception(
+                log_msg,
+                extra={"error_code": error_code, **log_extra},
+            )
+            user_msg = f"{MSG_BILLING_DETAILS_NOT_DEFINED_ERROR} ({error_code})"
+            raise web.HTTPServiceUnavailable(reason=user_msg) from exc
+
     return wrapper
 
 
diff --git a/services/web/server/tests/unit/isolated/test_products_model.py b/services/web/server/tests/unit/isolated/test_products_model.py
index b3ee823a37e..84fa67d94eb 100644
--- a/services/web/server/tests/unit/isolated/test_products_model.py
+++ b/services/web/server/tests/unit/isolated/test_products_model.py
@@ -76,3 +76,22 @@ def test_product_to_static():
         ],
         "isPaymentEnabled": False,
     }
+
+
+def test_product_host_regex_with_spaces():
+    data = Product.Config.schema_extra["examples"][2]
+
+    # with leading and trailing spaces and uppercase (tests anystr_strip_whitespace )
+    data["support_email"] = "  fOO@BaR.COM    "
+
+    # with leading trailing spaces (tests validator("host_regex", pre=True))
+    expected = r"([\.-]{0,1}osparc[\.-])".strip()
+    data["host_regex"] = expected + "   "
+
+    # parsing should strip all whitespaces and normalize email
+    product = Product.parse_obj(data)
+
+    assert product.host_regex.pattern == expected
+    assert product.host_regex.search("osparc.bar.com")
+
+    assert product.support_email == "foo@bar.com"
diff --git a/services/web/server/tests/unit/with_dbs/03/wallets/payments/test_payments.py b/services/web/server/tests/unit/with_dbs/03/wallets/payments/test_payments.py
index ed8b2868481..f6519735ed1 100644
--- a/services/web/server/tests/unit/with_dbs/03/wallets/payments/test_payments.py
+++ b/services/web/server/tests/unit/with_dbs/03/wallets/payments/test_payments.py
@@ -33,6 +33,9 @@
     PaymentsSettings,
     get_plugin_settings,
 )
+from simcore_service_webserver.wallets._constants import (
+    MSG_BILLING_DETAILS_NOT_DEFINED_ERROR,
+)
 
 OpenApiDict: TypeAlias = dict[str, Any]
 
@@ -312,6 +315,29 @@ async def test_complete_payment_errors(
     send_message.assert_called_once()
 
 
+async def test_billing_info_missing_error(
+    latest_osparc_price: Decimal,
+    client: TestClient,
+    logged_user_wallet: WalletGet,
+):
+    # NOTE: setup_user_pre_registration_details_db is not setup to emulate missing pre-registration
+
+    assert client.app
+    wallet = logged_user_wallet
+
+    # Pay
+    response = await client.post(
+        f"/v0/wallets/{wallet.wallet_id}/payments", json={"priceDollars": 25}
+    )
+    data, error = await assert_status(response, status.HTTP_503_SERVICE_UNAVAILABLE)
+
+    assert not data
+    assert MSG_BILLING_DETAILS_NOT_DEFINED_ERROR in error["message"]
+
+    assert response.reason
+    assert MSG_BILLING_DETAILS_NOT_DEFINED_ERROR in response.reason
+
+
 async def test_payment_not_found(
     latest_osparc_price: Decimal,
     client: TestClient,