MAC (Merchant Advice Code)

Last updated:September 11, 2025

You run a successful online store. Orders come in, and your system quietly handles payments in the background — subscriptions, recurring purchases, saved cards. One morning, your system tries to charge a card for a monthly subscription. The transaction is declined. No explanation. No shopper to ask. Just a failed payment.

Your retry logic kicks in. You try again later that day. Then again the next morning. Still declined. Eventually, the transaction is dropped. The sale is lost. And your system has logged three failed attempts — each one costing you time, network fees, and a hit to your approval rate.

But here’s the part most merchants never see: the issuer had already sent a signal. With the first decline, they include a small code — a Merchant Advice Code (MAC). It might've said: “Don’t retry right now. Wait.” Or, “This account is closed. Stop trying.” But your system didn’t act on it. Not because it ignored the advice — but because it didn’t understand it. That’s what MACs are: quiet, actionable messages from the issuer, passed through the card network, meant to guide your next move. They're not just technical metadata. They're a way to make smarter retry decisions, reduce unnecessary retries, and avoid higher fees that can come from repeated failed attempts.

MAC is how issuers talk to you.
MAC Control is how you learn to listen.

What is a MAC?

A short code sent by the issuer in the decline response to tell the merchant what to do next (retry, wait, or stop).
Think of it as “issuer guidance for your next move”.

What do the card networks do?

The card schemes - like Visa and Mastercard - don't create Merchant Advice Codes. But they play a critical role in how MACs work:

They define the MAC rules and codes
They deliver the MAC from issuer to acquirer to merchant
They enforce the rules - including applying higher fees if MAC guidance is ignored

In short: Issuer decides → Scheme delivers → Merchant acts (or absorbs higher costs for not acting).

Why MACs matter to you?

Card schemes like Visa and Mastercard use Merchant Advice Codes to help merchants make better decisions after a decline. Here’s how:

They reduce unnecessary retries that waste time and rack up costs
They improve approval rates by guiding you toward the right next step
They help you avoid higher fees that can result from retrying when you shouldn’t

Ignoring MAC advice = extra fees + compliance risk.

Unified MAC codes with retry restrictions & fees

Here are the simple rules for merchants:

🔴 Don’t retry — the issuer has clearly indicated the transaction shouldn’t be attempted again. Retrying may lead to higher costs.
🟠 Fix the issue first — something needs attention (e.g., expired card, insufficient funds). Retry only after resolving it.
🟡 Wait before retrying — the timing isn’t right. Retrying too soon could result in additional fees or lower approval rates.

MAC	Likely decline reason	Description (Issuer advice)	Fee Rules
🟠MAC01	Account needs update or Strong Customer Authentication (SCA) required	Retry with updated card info or 3DS	No fixed fee, but retrying without fixing may lead to compliance risks
🟡MAC02	Credit limits issue, insufficient funds	Retry after 72 hours	Monitored Higher fees if retries exceed 15 in 30 days
🔴MAC03	Account closed or fraud suspected	Do not retry. Obtain new payment method	Higher fee per retry
⚪MAC04	Token setup issue	Retry with correct token configuration	No additional fee expected
🔴MAC21	Customer canceled recurring agreement	Do not retry. Cardholder opted out	Higher fee per retry
🟠MAC22	Merchant not eligible for installment product	Do not retry	No fixed fee, but retrying may be considered non-compliant and lead to higher costs
🟡MAC24	Temporary funding issue	Retry after 1 hour	Risk if retried too soon
🟡MAC25	Temporary funding issue	Retry after 24 hours	Risk if retried too soon
🟡MAC26	Temporary funding issue	Retry after 2 days	Risk if retried too soon
🟡MAC27	Temporary funding issue	Retry after 4 days	Risk if retried too soon
🟡MAC28	Temporary funding issue	Retry after 6 days	Risk if retried too soon
🟡MAC29	Temporary funding issue	Retry after 8 days	Risk if retried too soon
🟡MAC30	Temporary funding issue	Retry after 10 days	Risk if retried too soon
⚪MAC40	Consumer non-reloadable prepaid card used	Informational only	No additional fee
⚪MAC41	Single-use virtual card used	Informational only	No additional fee
⚪MAC42	Sanctions screening triggered	Do not retry. Cardholder or transaction matched a sanctions list or exceeded a sanctions scoring threshold	High compliance risk
⚪MAC43	Multi-use virtual card is usedt	Informational only. May appear on approved or declined transactions	No additional fee

How MAC Control solves the problem for merchants

Let’s go back to that moment — a transaction is declined, and your system is left to decide: retry or not? You received a 🔴MAC03 — the account is closed. Or maybe 🟡MAC02 — insufficient funds. Or 🟠MAC01 — the card needs updating.

Now what?

You could build logic to interpret each MAC. You could track scheme rules, retry windows, and fee thresholds. And yes — it is the merchant’s responsibility to follow issuer advice. But MAC Control simplifies this by automating the complexity. Once enabled, MAC Control reads the MAC, understands the issuer’s advice, and makes the decision for you — instantly.

Here’s how MAC Control acts on common MACs:

🔴MAC03 / 🔴MAC21 “Do not retry”, MAC Control blocks the transaction immediately and prevents retries for 30 days
🟡MAC02 / 🟡MAC24-30 “Retry after delay”, MAC Control blocks the transaction temporarily.
🟠MAC01 “Update account info”, MAC Control blocks retries for 7 days unless credentials are refreshed via account updater or network token lifecycle events
🟠MAC01 “Strong Customer Authentication (SCA) required”, MAC Control blocks retries for 7 days to allow you enable 3DS on your channel
🟠MAC22 “Not eligible for a product”, MAC Control blocks retries for 30 days allowing time to review eligibility with the scheme"

You make smarter retry decisions — based on issuer signals, not guesswork.
You reduce unnecessary costs — by avoiding retries that lead to higher fees.
You focus on your business — not on interpreting obscure decline codesYou stay compliant.

Where MAC Control applies

Every time your system sends a transaction — whether it’s a saved card, a subscription renewal, or a digital wallet payment — MAC Control is quietly watching. It doesn’t act on everything. Only when it matters.

When a transaction involves a PAN, DPAN, or network token, and a MAC is present, MAC Control steps in. It applies to a wide range of authorization types — from pre-auths and debits to rebills, fast refunds, online reversals, and credits.
MAC Control checks the MAC and determines the next step: retry, wait, or stop. It’s designed to work across acquirers — but only where MAC support is available. Not all acquirers expose MACs today, so MAC Control applies selectively based on acquirer capabilities.

How MAC Control decides to block or allow a retry

Account-Level Issues

MAC Control blocks retries when the issue is tied to the cardholder’s account or the merchant’s eligibility — not the specific transaction. These include:

🟠 MAC01 – Cardholder account needs update or Strong Customer Authentication (SCA) required
🔴 MAC03 – Cardholder account closed or fraud suspected
🟠 MAC22 – Merchant not eligible for installment product

If the PAN, wallet DPAN, or network token DPAN hasn’t changed, retrying will almost always fail again. Changing the amount, currency, or merchant transaction ID won’t help — the issue is structural, not transactional.

Why?

The cardholder's account is expired or closed
The merchant isn’t eligible for the product (e.g., installments)
Strong Customer Authentication (SCA) is required but hasn't been completed

Example:

The card expired → No retry will succeed until it’s updated
Strong Customer Authentication (SCA) required → Retry is blocked until authentication is completed

Transaction-Level Issues

Some MACs point to issues tied to the specific transaction — such as the amount, order, or recurring agreement. These include:

🟡 MAC02 / MAC24–30 – Credit limits or insufficient funds
🔴 MAC21 – Customer canceled a recurring agreement

In these cases, MAC Control doesn’t block all retries — only identical retries of the same transaction. Merchants retain flexibility to adjust and retry under different conditions.