Cause code used in error responses.

ERROR_CAUSE_UNSPECIFIED The cause of the error is unknown or is not specified below.
INVALID_NUMBER The phone number provided in the request is invalid. This error cause should be used for all requests that failed due to a bad phone number (e.g., the 404 NOT FOUND error).
INCOMPATIBLE_PLAN The plan included in the request is incompatible with the user. See purchase plan API call in data plan agent API specification.
DUPLICATE_TRANSACTION The requested transaction is a duplicate of a previous transaction. See purchase plan API call in data plan agent API specification.
BAD_REQUEST Original request was malformed.
BAD_CPID The CPID provided in the request has expired or is otherwise unrecognized.
BACKEND_FAILURE While the DPA itself is operational, the backend necessary to complete the request is not.
REQUEST_QUEUED The DPA has queued a request for processing but the outcome of the request is still pending. The client may retry the request to retrieve the result of the request. The DPA will return REQUEST_QUEUED to requests that arrive before processing of the original request has completed.
USER_ROAMING The CPID endpoint or the DPA received a request for a user who is currently roaming.
USER_OPT_OUT User has not opted in the program.
SIM_RELOAD_REQUIRED The phone number provided in the request is in a "grace period" where a subscriber can receive incoming calls but cannot use mobile data. User has to top up credits or buy data packs to get out of this state.
TOO_MANY_REQUESTS GTAF is making too many requests to the DPA.
PAYMENT_MISSING The operator does not have a way to charge the user for purchase.
INVALID_IMSI The IMSI provided is invalid or inactive
INELIGIBLE_FOR_SERVICE User is not eligible for the requested service
SERVICE_UNAVAILABLE Requested service is unavailable. Please retry later
SERVICE_NOT_SUBSCRIBED Service is not subscribed by user
ACCOUNT_SUSPENDED User account is inactive or suspended