A Merchant Identification Number (MID) is a unique, typically 15-digit code assigned to a business by their acquiring bank or payment processor. It serves as the business's unique account number within the payment processing ecosystem, allowing the card networks to route funds accurately to the merchant's bank account after a transaction.
One Business, Multiple MIDs
A single corporate entity can hold multiple MIDs. For example, a business might have one MID for its e-commerce website, a second MID for its physical brick-and-mortar store, and a third MID for processing high-risk subscription billing. Acquirers must track the risk of all MIDs associated with a single Ultimate Beneficial Owner (UBO).
Unifying MID Risk via Onlayer
Fraudsters often try to "burn" one MID with excessive chargebacks while quietly opening a new MID with the same acquirer. Onlayer prevents this using advanced entity resolution. By correlating seemingly disparate data points, Onlayer connects multiple MIDs to their true owners, allowing you to manage risk holistically and apply customized decision rules across your entire portfolio.
