Issuer declines carry an instruction: update credentials, retry later, or stop. PayOS surfaces it.
Start using PayOS, pay per use. No sales call required.
Under Mastercard’s Transaction Processing Excellence program, issuers attach a Merchant Advice Code to their response. The decline says no. The MAC says what to do about it.
These are the advice codes PayOS returns on a pre-auth lookup. Tap one to see it. No number memorization required.