We have some very rare cases (less than 1 in 10000) where we don't have a SIM Activation time stamp in our platform.
The mobile phone number is however valid, and belongs to KPN.
Currently we are returning a null value in stead of a time stamp in the reply body.
It may be better however to return an error code instead
(also to avoid confusion also when there is a limitation becuase of privacy reasons).
What is the error code to return in this case?
Should we use a 422 error with code NOT_SUPPORTED and message Service not supported for this phoneNumber ?
Or would it be better to provide a 204 error code (No Content) ??
Please advice what is best.