What Chargeback Ratio Gets a Peptide Merchant Shut Down? Visa VAMP and Mastercard ECM in 2026

How does Visa calculate the VAMP ratio?

Visa folded its fraud and dispute monitoring programs into one program, the Visa Acquirer Monitoring Program (VAMP), with thresholds effective June 1, 2025 (Visa VAMP fact sheet). The ratio counts transactions, not dollars:

VAMP Ratio = Count of [Fraud (TC40) + Disputes (TC15)] ÷ Count of Settled Transactions (TC05)

TC40 is a fraud report filed by the card issuer. TC15 is a dispute. TC05 is a settled sale. One sale that draws a fraud report and then a dispute can count twice. So the dispute rate in a processor dashboard can understate the number Visa watches.

Two things come out of the count, subject to the timing of Visa’s data extract: disputes resolved through pre-dispute tools, and fraud reports that qualify for Compelling Evidence 3.0.

What are the current VAMP thresholds?

The merchant line only applies when the bank’s own portfolio is not already flagged. That is why banks watch individual merchants against lines much tighter than 1.5%.

Older numbers still circulate. Posts that quote 0.65%, 0.9% or 1.8% describe Visa’s earlier dispute monitoring program, which VAMP replaced.

What do these numbers mean for a small peptide store?

The 1,500 count floor means a small store may never be identified by VAMP itself. That does not make it safe. The merchant agreement sets the limits that apply day to day. Visa’s own Dispute Management Guide (October 2026) says a merchant’s responsibilities “are usually explained in your merchant agreement.”

For scale: at 2,000 Visa sales a month, 1.5% is 30 fraud reports and disputes. 0.7% is 14. A few bad weeks move a small store’s ratio a long way.

How does Mastercard measure chargebacks?

Mastercard’s Excessive Chargeback Merchant (ECM) program uses two tests at once. A merchant ID must exceed both the count and the ratio (J.P. Morgan ECM FAQ, February 2022; Mastercard AN 2968, January 2020).

• The ratio is this month’s chargebacks divided by last month’s transactions. A month with falling sales pushes the ratio up even if chargebacks stay flat.
• All first-presentment chargebacks count. Winning a representment later does not take one out of the count.
• Once in the program, a merchant ID stays until it posts three consecutive months below the thresholds.
• In the high excessive tier, issuers collect a USD 5 recovery assessment for each chargeback over 300.

When does a chargeback problem turn into a MATCH listing?

MATCH is Mastercard’s list of merchants terminated for specific reasons. Reason code 04, Excessive Chargebacks, applies when Mastercard chargebacks over the previous three months exceeded 1.5% of sales transactions in a month and totaled at least USD 5,000 (Mastercard Security Rules and Procedures, February 11, 2025). A listing stays on MATCH Pro for five years. When a bank terminates a merchant for a listed reason, the rules say it must add the merchant.

A listing is not a permanent ban. The same rules say an acquirer “may onboard” a listed merchant. Expect a much closer review.

What changed in 2026?

• April 1, 2026: Visa’s US merchant line dropped from 2.2% to 1.5% (VAMP fact sheet, footnote 5).
• Late July 2026: Mastercard’s Scam Merchant Monitoring Program took effect. Acquirers must start an investigation within 72 hours when potential scam activity hits a risk threshold, and give extra scrutiny to merchants with under six months of processing history (Payments Dive, July 27, 2026).
• October 24, 2026: Visa expands Compelling Evidence 3.0 for card-absent fraud disputes (condition 10.4), including multi-merchant transactions as evidence (Visa Core Rules, April 18, 2026 edition, summary of changes).

For a new peptide store, the Mastercard change matters most. The first six months of processing now get extra attention by rule.

What actually lowers a peptide store’s ratio?

Prevention beats fighting. Merchants won 17.1% of fraud-coded chargebacks and disputes in 2025, per the Merchant Risk Council’s 2025 Global eCommerce Payments & Fraud Report. Most of the work is keeping the dispute from happening.

• Make the billing descriptor match the store name. Visa’s Dispute Management Guide says customers are “more likely to question a charge when the business name appearing on their statement differs from the name they recognize.” Put the descriptor in the order confirmation email too.
• Use 3-D Secure (Visa Secure) on card-not-present orders. Visa’s guide says fully authenticated transactions can qualify for protection from fraud-related disputes. It also notes that merchants flagged in Visa’s monitoring program can still face condition 10.5 disputes.
• Enroll in pre-dispute tools through the processor, such as Visa’s Rapid Dispute Resolution and Order Insight. Disputes resolved there are excluded from the VAMP ratio. A refund is still a refund, so fix the cause too.
• Keep the order data that Compelling Evidence 3.0 relies on, such as device ID or IP address, for every order. Visa’s guide describes linking a disputed sale to at least two earlier undisputed transactions from within the prior 365 days.
• Ship with tracking and keep delivery records. Visa’s guide lists proof of delivery, with the full delivery address and courier status, as evidence for physical goods.
• Refund quickly when a buyer is unhappy. A refund costs the sale. A dispute costs the sale, a fee, and room under the threshold.
• Track fraud reports, not just disputes. Ask the processor for TC40 counts. They are half of the VAMP numerator.

What should never be done to manage the ratio?

• Splitting volume across extra merchant accounts to stay under the line. Stripe’s policy page lists “evasion of card network chargeback monitoring programs” as a prohibited use.
• Running sales through another business’s merchant account. Mastercard defines that as transaction laundering, and it is its own MATCH reason code (03).
• Padding the denominator with small sham transactions. The US Department of Justice described that pattern in its December 2023 complaint against CB Surety. The complaint states allegations.

Each of these makes the account look safer than it is. When the bank finds out, closure and a MATCH listing are both on the table.

If a ratio is already climbing, talk to the processor before the month closes, then fix the source. For an outside read on a current setup, send it to us. Related: rolling reserves, Does Stripe allow peptides?, and our retail (B2C) and wholesale (B2B) programs. More on how we work with merchants.

Sources

1. Visa Acquirer Monitoring Program (VAMP) fact sheet, Visa, v2, 2025; Apr 1, 2026 change in footnote 5.
2. Visa Dispute Management Guide for Merchants, Visa, Oct 2026.
3. Visa Core Rules and Visa Product and Service Rules, summary of changes, Visa, Apr 18, 2026 edition.
4. Mastercard Excessive Chargeback Program FAQ, J.P. Morgan Merchant Services, Feb 2022.
5. AN 2968: Acquirer Chargeback Monitoring Program, Mastercard (hosted by an acquirer), Jan 2020.
6. Security Rules and Procedures, Merchant Edition (MATCH), Mastercard, Feb 11, 2025.
7. “Mastercard bolsters scam defense”, Payments Dive, July 27, 2026.
8. 2025 Global eCommerce Payments & Fraud Report, Merchant Risk Council, 2025.
9. Prohibited and Restricted Businesses (prohibited uses), Stripe, last updated Sept 22, 2026.
10. United States v. CB Surety LLC, complaint, US Department of Justice, filed Dec 2023.