Visa’s new fraud monitoring framework gets its teeth on October 1, 2025, when merchants’ acquiring banks are held to a new chargeback and fraud standard and a new fee structure.
The Visa Acquirer Monitoring Program replaced two Visa fraud and chargeback programs in April 2025, introducing a combined measure called the VAMP ratio.
Visa granted acquiring banks and, indirectly, merchants six months to prepare for VAMP ratio enforcement and its potential fees. The “advisory” period ends September 30, 2025, and some acquirers could incur a $10 fee (or more) per chargeback. VAMP enforcement, however, rolls out in phases through 2026.
Visa estimates the new VAMP framework could help acquirers detect four times more fraud than the old system, potentially saving more than $2.5 billion in annual losses.
Visa’s VAMP framework aims to reduce credit card fraud.
Indirect Impact
The VAMP targets acquirers — the banks, processors, and payment facilitators that provide merchants with access to the Visa network. Visa imposes penalties on these acquirers since it contracts with those companies, not merchants directly.
For enterprise-level ecommerce or omnichannel retail businesses, this acquirer distinction could matter less than one might think.
Acquirers are responsible for their merchant portfolios and are likely to hold them to VAMP standards. Thus, if a merchant’s dispute or fraud rates climb, the acquirer may respond with higher fees, stricter rules, or even account termination as a last resort. (As an aside, Shopify Payments is an acquirer and thus subject to VAMP.)
VAMP Ratio
The VAMP ratio is the program’s key metric. Visa calculates the ratio by adding reported fraud cases (known as TC40s) and chargeback cases (TC15s), then dividing by the number of settled Visa transactions.
Visa issues TC40 reports when a shopper reports an unauthorized charge, regardless of whether the claim evolves into a full-blown dispute.
Conversely, a TC15 or chargeback is a transaction dispute that may or may not be related to a fraud claim.
One wrinkle is that VAMP counts fraud-related chargebacks twice — once as fraud (TC40) and once as a dispute (TC15).
This double-counting makes VAMP ratios relatively more strict than the old system. Visa’s reported rationale is that fraud, which escalates into a chargeback, is doubly damaging and should carry more weight.
So-called friendly fraud, when a customer lies about not receiving goods, would also, unfortunately, be counted twice.
Thresholds
VAMP has three primary thresholds at the time of writing.
- Acquirer Above Standard includes processors with a portfolio-wide VAMP ratio of 0.50% or higher. Acquiring banks in this category will be subject to a Visa penalty of $5 per fraudulent or disputed transaction, effective January 1, 2026.
- Acquirer Excessive describes processors with a portfolio VAMP ratio of 0.70% or higher. These acquirers will pay $10 per dispute, effective on October 1, 2025.
- Merchant Excessive is the VAMP threshold for individual merchants within the acquirer’s portfolio that have a ratio of 2.20% or higher, with at least 1,500 fraud and dispute transactions in a month. Acquirers must pay an additional $10 per disputed transaction for these sellers.
In short, Visa wants acquirers to take chargebacks and payment card fraud much more seriously.
Enumeration Attacks
VAMP also monitors and penalizes acquirers for merchants that fail to prevent large-scale “enumeration” or card number testing attacks, where fraudsters run thousands of authorization attempts to guess card details.
Acquirers are subject to fines or other actions when a merchant’s enumeration attempts exceed 300,000 per month or when 20% of total authorization requests come from fraudsters.
Relatively simple steps, such as CAPTCHA tests or limits on authorization attempts, should thwart most attacks.
Impact
VAMP applies only to sellers with 1,500 or more disputed charges (TC40 plus TC15) per month. Thus most ecommerce SMBs will continue to pay $15 to $30 for a chargeback but will not incur further Visa monitoring.
Large retailers, however, may want to monitor their VAMP ratios to avoid warnings, reserve requirements, or even offboarding from their acquirer.
In general, merchants with no significant issues under Visa’s fraud and chargeback programs are likely to experience minimal impact from VAMP.