The following error codes can be raised by the Verify web service calls:
CountryIsoCode field is invalid due to not following ISO 3166-1 alpha 3
From field contains characters outside the GSM character set
From field is empty.
From field is longer than the maximum numeric length of 15.
From field is longer than the maximum alphanumeric length of 11.
From field is shorter than the minimum alphanumeric length of 2.
From field is reserved and cannot be used by your account
If your account is pay as you go, this error will be returned if there is insufficient credit on the account to complete the requested operation.
The supplied JSON payload is not formatted correctly, e.g. missing required parameters or doesn't conform to JSON format.
To field is empty
To field is invalid due to the phone number not being formatted correctly, e.g. too long, too short, not a number.
ValidUntil field is before the current time and the message cannot be sent
ValidUntil field is invalid due to time being more than 30 minutes in the future.
Maximum frequency of sending to a single phone number from your account has been exceeded.