A Postal code is required based on country. With KSA for example, it is a mandatory requirement. This requirement is part of the billing information that is required by the processor and by anti-fraud systems to ensure the security and integrity of the transaction and the cardholder.
Suggestion: Google the Zip Codes in your Area.
Accordingly to our Established list, which was coined from the International Standard (ISO), all regions appear to be covered.
Sources: https://en.wikipedia.org/wiki/ISO_3166-2:SA and https://www.iso.org/obp/ui/#iso:code:3166:SA
Example: KSA
Example: KSA
Our system contains all official ISO Saudi regions (there are 13 in total).