The VAMP Merchant Playbook: What Changes April 1, 2026

Three things move at once, and none of them move in the merchant's favor.

• The merchant Excessive threshold dropped from 2.2% to 1.5%. A merchant that sat comfortably under the old line by a wide margin can land over the new one without changing anything about how it does business.
• The monitoring floor moves to 1,500 combined fraud reports and disputes per month. Below that count, a merchant's ratio isn't scored at all — Visa treats the sample as too small to be statistically meaningful. Once a merchant crosses 1,500 combined events in a calendar month, both the ratio and the fee described below start to apply.
• A flat $8 fee landed on every disputed transaction once a merchant is scored Excessive, with no warning tier in between. Earlier dispute-monitoring programs built in an early-warning stage — a period where a merchant that tripped the initial threshold received a notice and a reduced or waived fee before harder enforcement began. That buffer has been removed. A summary of the updated VAMP thresholds compiled by cside describes the same shift: the ramp that used to give merchants time to react is now compressed into a single step.

At a representative exchange rate of $1 ≈ €0.92, that $8 fee works out to roughly €7.36 per disputed transaction. That is not a rounding error once a merchant is generating a few thousand disputes a month — it is a direct, per-unit cost that scales with volume rather than capping out at a flat monthly penalty.

The combination of a lower threshold, a firm monthly floor, and an immediate fee means the cost of a rising dispute rate compounds faster than it used to. A merchant that used to have a quarter to course-correct now effectively has the current billing cycle.

Here is the part of VAMP that catches merchants off guard even when their own numbers look fine: acquirers are scored too, on a much tighter scale.

Visa sets acquirer-level thresholds at 0.3% for "Above Standard" and 0.5% for "Excessive" — measured across the acquirer's entire processed portfolio, not merchant by merchant. Those numbers are roughly a fifth of the merchant-level 1.5% line. An acquirer processing tens of millions of transactions a month across hundreds of merchants has to keep its blended combined-ratio well below the level any single merchant is allowed to reach on its own.

That gap is the trap. A merchant running at 1.4% — under the new merchant Excessive line — can still represent a disproportionate share of an acquirer's total dispute volume, especially with a smaller or mid-size acquirer whose overall book is thinner. The acquirer doesn't get to average out one high-dispute merchant against a thousand quiet ones if its portfolio isn't that large to begin with. Because the acquirer's threshold sits so much lower than the merchant's, a merchant that looks "fine" by its own scorecard can be the exact reason its acquirer tips into Above Standard or Excessive territory.

A merchant that clears its own VAMP line is not automatically safe.

Acquirers respond to their own portfolio risk with reserves, tighter terms, or account termination — sometimes for merchants who are technically within their individual limits — because it is the acquirer, not the merchant, that carries Visa's liability for the whole book.

This is also why acquirers increasingly ask merchants for dispute-reduction plans well before a merchant's own ratio reaches 1.5%. They are managing to their own 0.3%/0.5% ceiling, not the merchant's.

The intuitive response to a rising dispute ratio is to get more conservative: decline more borderline transactions, add friction, tighten fraud rules. Under VAMP, that instinct frequently backfires, and the mechanism is worth spelling out because it isn't obvious from the ratio alone.

The VAMP ratio is combined fraud reports and disputes divided by total transaction count. Blocking a transaction before it settles removes it from the denominator — total processed volume goes down. But it does nothing to the numerator, because the disputes and fraud reports already logged this month came from transactions that were approved days or weeks earlier, inside the dispute window card networks allow. You cannot retroactively erase a chargeback that has already been filed by declining a different, unrelated transaction today.

Worse, the transactions a merchant blocks in a panic are disproportionately legitimate. Genuine fraud, run by people who actively test and adapt to detection rules, tends to keep getting through simple velocity checks and blanket declines. So the mix that gets cut is heavy on real customers and light on actual fraud — the denominator shrinks, the numerator holds steady or barely moves, and the ratio gets worse, not better.

There is a second cost layered on top: every legitimate transaction declined is revenue the merchant simply loses. A merchant chasing a lower ratio through blanket declines can end up with a worse ratio, a higher fee bill, and lower sales — a strictly worse position on every axis.

Numbers make this easier to see. Take a merchant processing 200,000 transactions a month.

Starting position. The merchant logs 3,200 combined fraud reports and disputes in a month. That's a ratio of 1.6% — above the new 1.5% Excessive threshold that took effect April 1, 2026, and well above the 1,500-event monitoring floor, so the merchant is fully in scope. At $40 per disputed transaction, the fee bill for that month is:

3,200 × $8 = $128,000, or roughly €117,760 at $1 ≈ €0.92.

The over-blocking reaction. Alarmed, the merchant tightens its fraud filters and declines an additional 40,000 transactions it judges "risky," dropping approved volume from 200,000 to 160,000. The underlying fraud attempts don't stop — most of what gets blocked is legitimate customers caught by broader rules — so the combined fraud-and-dispute count only edges down slightly, to 3,100. The new ratio:

3,100 ÷ 160,000 = 1.94%.

The merchant's ratio got worse, not better, despite blocking a fifth of its volume. The fee bill barely moves — 3,100 × $40 = $124,000, about €114,080 — while the merchant has also given up 40,000 legitimate sales it can never recover. Three losses from one decision: a worse ratio, essentially the same fee, and lost revenue.

The acquirer-level knock-on. Now layer in the acquirer's exposure. Say this merchant's acquirer processes 20,000,000 transactions a month across its full portfolio. Before this merchant's contribution, the acquirer's other merchants generate 57,300 combined fraud reports and disputes — a ratio of 0.2865%, just under the 0.3% Above Standard line. Add this merchant's original 3,200 events:

(57,300 + 3,200) ÷ 20,000,000 = 0.3025%.

A single merchant running a "moderate" 1.6% ratio of its own — one that, on paper, looks manageable — tips its acquirer over the Above Standard threshold on a portfolio thirty times its own size. If the merchant then swings into the over-blocking scenario above, the acquirer's exposure doesn't improve either, because the acquirer's own transaction volume from that merchant also shrank, while the dispute count barely changed.

This is the full VAMP trap in one example: a merchant reacting to its own scorecard can simultaneously worsen its own ratio, keep its fee bill flat, lose sales, and still make its acquirer's portfolio-level problem worse.

Waiting for the monthly statement to find out where you stand is no longer viable once the fee applies with no warning tier. A few concrete steps matter more now than they did under the old thresholds.

• Track your combined ratio against 1.5%, not 2.2%. Update internal alerting thresholds now, well ahead of the April 1 change, so nobody is still watching the old line.
• Watch absolute counts once you're near 1,500 combined events a month. The floor means small merchants can ignore the ratio; anyone near or above it can't.
• Ask your acquirer or gateway for portfolio-level visibility, not just your own merchant number — the acquirer-level thresholds are what ultimately drive account-level decisions.
• Invest in fraud tools that reduce genuine fraud without blanket declines — 3DS and Strong Customer Authentication (SCA) reduce fraud without removing legitimate transactions from your denominator the way blunt rule-based blocking does.
• Fix root causes of disputes — delivery timelines, billing descriptors, refund friction — rather than treating the ratio as a fraud-filter problem alone. A large share of "fraud" reports are friendly fraud driven by confusion, not criminal intent, and those are addressed with clearer receipts and faster refunds, not tighter declines.

Cost+ doesn't run VAMP scoring for merchants, and this program sits at the Visa network and acquirer level rather than inside any single processor's pricing. But visibility into cost still matters here: Cost+'s IC++ (Interchange Plus Plus) pricing itemizes interchange, scheme fees, and our markup separately on every transaction, and the default chargeback fee is a flat €30 per case — clearly separated from any network-level dispute fee like the one described above, rather than folded into a single opaque rate. If you're trying to understand your true cost per disputed transaction across every layer — network, acquirer, and gateway — that itemization is the starting point. Talk to our team through the contact page if you want help mapping where each fee in your dispute chain actually comes from before the April 2026 thresholds take effect.