---
title: "Merchant Underwriting"
url: "https://mahouse.world/glossary/merchant-underwriting"
type: "glossary term"
topic: "Fraud & risk"
author: "Ihor Vlasov"
reviewed: "2026-09-20"
published: "2026-08-10"
---

# Merchant Underwriting

Merchant underwriting is the acquirer's or payment facilitator's assessment of a merchant before it may accept cards: what it sells, to whom, how far ahead of delivery it takes money, its finances, its owners, its history — to decide whether to accept it, at what price, and with what reserve. The acquirer is extending a credit line equal to the merchant's undelivered sales, and underwriting sizes that exposure.

**Also known as:** Merchant risk assessment, Merchant onboarding review, Acquirer underwriting

## Key facts

- **Used at:** onboarding of every merchant and sub-merchant, periodic review, and on triggers — a spike in volume, in chargebacks or in refunds
- **Binding:** the scheme rules require acquirers to underwrite merchants and to police prohibited categories; the acquirer's own credit policy and the merchant agreement set reserves and termination rights
- **Typical inputs:** KYB and beneficial ownership; the merchant category code and the scheme's high-risk lists (travel, gambling, adult, nutraceuticals, crypto); the delivery gap between payment and fulfilment; average ticket and volume; refund and chargeback history from previous acquirers (the MATCH list of terminated merchants); financial statements for larger merchants; website review for what is actually sold
- **Typical outputs:** accept or decline; a pricing tier; a reserve (rolling 5–20% for 90–180 days, or a fixed amount); settlement delay; volume caps; a review date
- **Parties:** the acquirer's or facilitator's risk team, the merchant, the schemes (whose rules and lists frame it), and the sponsor bank behind a facilitator

## How merchant underwriting works in practice

A travel agency applies to an acquirer. The underwriter reads: KYB clean; merchant category 4722, on the scheme's high-risk list; average ticket €1,800; €3m of monthly volume; payment taken at booking, travel on average 70 days later. The exposure is the undelivered travel — about €7m at any time — because if the agency fails, every cardholder with a booking charges back and the acquirer pays. The underwriter accepts with a 10% rolling reserve on 180-day terms, a three-day settlement delay, a €4m monthly cap for the first six months, and a review at that point; the pricing tier reflects the risk. A furniture retailer with two-day delivery and the same volume gets no reserve and next-day settlement.

The judgement is about what could go wrong and how much it would cost. A subscription business's risk is chargebacks from forgotten renewals; a marketplace's is sellers who do not ship; a nutraceutical merchant's is the scheme's monitoring programme; a crypto exchange's is everything. Payment facilitators underwrite thousands of small merchants by rule and a few large ones by hand, and the scheme rules force a full underwriting once a sub-merchant passes a volume threshold. The reserve is the tool that turns judgement into protection: money held back against the losses the underwriter thinks possible.

For a buyer of an acquiring business the underwriting files and the reserve book are the credit diligence: who is on the book, what could fail, and what is held against it.

## Example

A payment facilitator underwrites 2,000 sub-merchants a month by automated rules — KYB, category, website check, ticket size — clearing 85% instantly with standard terms. The 15% routed to underwriters include a ticketing platform selling events six months ahead: €600,000 a month, all pre-delivery. The underwriter sets a 15% rolling reserve for 180 days and a settlement delay of five days, and asks for the event insurance policy. Eight months later the platform's largest festival is cancelled; €1.4m of tickets are charged back over six weeks; the reserve holds €540,000, the platform's own refunds cover €700,000, and the facilitator's loss is €160,000 — against the €1.4m an unreserved onboarding would have cost. The rule that routed the platform to a human was "delivery gap over 60 days".

## Common mistakes

- Underwriting on volume and ignoring the delivery gap, which is the exposure.
- Accepting a merchant's declared category without reading its website.
- No re-underwriting when volume triples in a month.
- Reserves released on a calendar rather than on the exposure running off.
- Facilitators onboarding faster than their rules can see, and inheriting the merchants nobody else would take.

## Related terms

- [Acquirer](https://mahouse.world/glossary/acquirer.md)
- [Payment Facilitator](https://mahouse.world/glossary/payment-facilitator.md)
- [Counterparty Risk](https://mahouse.world/glossary/counterparty-risk.md)
- [Rolling Reserve](https://mahouse.world/glossary/rolling-reserve.md)
- [Know Your Business](https://mahouse.world/glossary/know-your-business.md)
- [Chargeback Ratio](https://mahouse.world/glossary/chargeback-ratio.md)

— Ihor Vlasov, M&A FinTech Expert. Last reviewed 2026-09-20. https://mahouse.world/authors/ihor-vlasov