OFAC screening for payment processors explained

How processors should run sanctions checks on every transaction and merchant without choking legitimate volume.

TL;DR

TL;DR: A payment processor must screen merchants at onboarding and check each transaction against the SDN List, because a processor that settles a payment for a blocked party is itself violating OFAC. Civil penalties start at $356,000 per violation.

Onboarding is the first gate

Before a merchant goes live, the processor should verify the entity and its beneficial owners against the Specially Designated Nationals and Blocked Persons List. The 50 Percent Rule matters at this stage: an entity 50 percent or more owned by a blocked person is itself blocked, so ownership screening must reach through to the individuals behind the business.

Every transaction is an exposure point

A processor sits between payers and payees, so the settlement it performs is a money movement it facilitates. OFAC is a strict liability regime: intent is not required, and the processor cannot rely on the merchant having done its own check. Transaction-level screening against a current list is the standard defense, run before settlement rather than in a nightly batch.

Automation keeps it fast and honest

agentmail fits this as an API the processor calls mid-transaction: one HTTP call under 100 ms returns clean (ALLOW) or flagged (BLOCK), using 947 OFAC-listed crypto wallets and 19,218 SDN names synced hourly. A free tier of 5 checks per day, with paid tiers up to 100,000 checks per month, lets a processor start screening without a contract.