The 'phone number mask' field under Poscfg / Gss / Restaurant should be adjusted according to the digit count of the phone number that appears on the incoming call. For example, if the incoming call is received in 05xx-xxxxxxx format, phone number mask should be written as (0000) 000-0000.
Also, it should be regarded if the area codes are shown before the numbers of local calls on manually done GSS record entries and entries should be done accordingly. If no area code is shown, then the area code should also not be entered to the manually done entries.