Mastercard GMAP Guide 2027: The Global Merchant Audit Program Explained

What GMAP Changes

Mastercard's Global Merchant Audit Program (GMAP) is a new merchant and acquirer monitoring system launching April 1, 2027. It replaces four existing programmes in one move: the Excessive Chargeback Merchant (ECM), Excessive Fraud Merchant (EFM) and High Excessive Chargeback Merchant (HECM) programmes for merchants, and the Acquirer Chargeback Monitoring Program (ACMP) for acquirers.

The headline change is what counts toward your ratio. Today's programmes count chargebacks. GMAP counts fraud and disputes together — a transaction reported as fraud to Mastercard's Fraud and Loss Database counts against you even if the cardholder or issuer never files a formal chargeback.

The New Combined Fraud + Dispute Metric

GMAP's ratio combines two things that used to be tracked separately:

Two things make this different from today's ECM/HECM calculation. First, fraud is counted even when no chargeback was ever filed — a merchant who identifies and voluntarily refunds fraudulent orders (or whose issuer flags fraud without disputing) still has that fraud counted here. Second — and this is where industry sources disagree — some analyses describe the ratio as calculated by transaction count, others by dollar amount. Neither interpretation has been confirmed against an official Mastercard source, since the original bulletin isn't public.

New Merchant Categories: HDM and EDM

To land in a GMAP merchant tier, all three conditions must be met in the same month — a minimum transaction count, a minimum dollar amount, and the ratio threshold:

Fine schedules

To exit HDM or EDM, a merchant needs three consecutive months below the applicable threshold — one month longer than the two-month exit requirement under today's ECM programme.

New Acquirer Tiers: HDA and EDA

GMAP also replaces the Acquirer Chargeback Monitoring Program (ACMP) with two new acquirer-level tiers, applying once an acquirer processes 1,500+ transactions for a merchant relationship:

These thresholds are far below the 5% HDM trigger — and that gap matters. Because an acquirer faces its own fines for its merchant portfolio's combined ratio, acquirers are likely to start limiting volume, tightening reserves, or offboarding risky merchants well before those merchants individually reach the 5% HDM threshold. If your ratio is climbing, don't wait for the merchant-level trigger — your acquirer is watching a lower number.

How ECM, EFM and HECM Fold Into GMAP

The current chargeback-only programmes don't disappear so much as get absorbed. Two structural changes matter beyond the merger itself:

• Monitoring moves to the sub-merchant ID level. A platform or marketplace with many sub-merchants under one MID can no longer dilute one bad sub-merchant's ratio across the whole portfolio — each sub-merchant is watched individually.

• The legacy ECM ratio threshold steps down over several years, while the 100-chargeback monthly minimum stays in place.

A minimum of 100 chargebacks per month continues to apply throughout — a merchant with a high ratio but low absolute chargeback volume stays outside this particular gate, though the combined GMAP metric above has its own, separate 5-transaction/$5,000 gate that catches smaller merchants differently.

Key Dates

One more related change: the Questionable Merchant Audit Program (QMAP) is also being tightened alongside GMAP — its minimum volume trigger drops from $50,000 to $10,000, and its case review period shortens from 120 days to 30 days. Smaller and faster-moving cases will qualify for QMAP review than do today.

What This Means If You're Building or Using a Ratio Calculator

The single most important adjustment: fraud without a chargeback now counts. A calculator or internal spreadsheet that only tracks confirmed chargebacks will understate your real GMAP ratio — potentially significantly, for merchants with meaningful fraud-detection or voluntary-refund activity that never reaches a formal dispute.

Because sources disagree on count-based vs. amount-based calculation, the safest approach is to track both. Our GMAP calculator computes your ratio both ways side by side, so you can compare against whichever methodology your acquirer confirms.

Frequently Asked Questions