Merchant Advice Codes

Galileo supports the use of Mastercard’s merchant advice codes (MACs) to help reduce the number of declined recurring transactions for you or your issuer. The MAC contains information about the actions a merchant needs to take.

Galileo supports the following MAC codes:

Merchant Advice CodeDescriptionTrigger
03Do not try againAn account is closed and the associated PAN should not be reused or re-opened for the next 120 days.
40The card used is a non-reloadable prepaid cardA non-reloadable prepaid card is used.
41The card is a single-use virtual cardA single-use virtual card is used.

MAC 40 and 41 are important to prevent the storage of card information (card on file) for future transactions, ultimately reducing the likelihood of declines.

To receive MAC decisioning via the Auth API, the GMACD product parameter must be set to Y. In the Auth API payload, merchant_advice_code will contain one of the supported MAC 03, 40, and 41. The field is blank for all other types of transactions.

Contact Galileo if you are interested in enabling MACs for your program.


You have the option to override the suggested MAC using the Auth API. To override, the MACO product parameter must be set. You provide the new MAC value in merchant_advice_code in the Auth API response.

By choosing to override, you assume the responsibility for ensuring compliance with the MAC program requirements.

Contact Galileo if you are interested in enabling overrides.