You might experience this error message below when label generation has failed:
Error Message: "PostalCode error: INVALID."
Cause:
PostNord's API can occasionally reject a valid postal code (e.g., 503 44), when it is newly assigned or not yet updated in their system.
Note: This error can occur even when the post code is correct on Google Maps.
Fixes:
Look up the address on PostNord's Postal Code Search to find their code.
Update the customer's postal code to match — or use a nearby code for that street (e.g., 503 44 → 503 38).
The street address and city are what matter most. As long as those are correct, PostNord's drivers will still collect the return.