A merchant identification number (MID) is a unique identifier assigned to a merchant account by the payment processor or acquirer when an account is created. It is used to route transactions, monitor account-level activity, and report data to card networks. Merchants operating multiple business lines may have more than one MID.
A MID is different from a bank account number. A MID identifies your payment processing account. Your bank account number identifies the account where your funds are deposited.
Most card networks monitor fraud and chargeback activity on a per-MID basis.
It’s possible for one MID to breach thresholds while other MIDs remain safe.
It’s essential to know which MID corresponds to which part of your business if you run multiple operations. It is also helpful to keep MID information organized and easily accessible so you can have a more streamlined onboarding experience if you ever add new payment product.
For more than a decade, Jessica Velasco has been a thought leader in the payments industry. She aims to provide readers with valuable, easy-to-understand resources.
