ByteDecline codesFor Merchants

What are Merchant Advice Codes (MACs)?

Author
Brady Murray
Published
May 2, 2024
Updated
Sep 30, 2026
Read time
2 min

What are these MACs that occasionally show up in my payload response?

Don’t worry if you’ve never heard of MACs—many Merchants haven’t. They are still relatively new, having been adopted by Mastercard, with Visa following closely behind.

MACs, also known as a recommendation codes, are numeric codes that give Merchants more details around how to move forward with retrying a declined transaction. Think of them as another level to a decline code.

Integrating MACs into your payments strategy can be a powerful way to reduce wasted processing expenses and increase reauthorization settlement rates. Since reducing the number of failed authorization attempts may lead to higher future settlement rates, following advice codes may also improve your authorization relationship.

MACs build on the decline codes received. They go a level deeper, telling the Merchant if they should retry the card, how long to wait until retrying the card, or a reason why the card was declined.

See your processor for a complete list of codes. They can be your best resource for how to adapt MACs and remap codes as needed.

MAC codes, as of 2024, can include:

Code Meaning
01 New Account Information
02 Can’t Approve at This Time; Try Again Later
03 Do Not Try Again
04 Token Not Supported
21 Stop Recurring Payments
24 Retry After 1 Hour
25 Retry After 24 Hours
26 Retry After 2 Days
27 Retry After 4 Days
28 Retry After 6 Days
29 Retry After 8 Days
30 Retry After 10 Days
40 Consumer Non-Reloadable Prepaid Card
41 Consumer Single-Use Virtual Card Number