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.
A deep dive into MIDs
If you want to accept credit and debit card payments for the goods or services you sell, your business needs a merchant account. And if you have a merchant account, you’ll have a merchant ID (MID).
A MID is a unique identifier. Only your account uses that particular combination of numbers and letters. Like a phone number that directs calls to your personal phone or an email address that sends messages to your individual inbox, a MID ensures funds are routed to your account and no one else’s. And, it prevents other businesses’ chargebacks from becoming your liability.
How are MIDs issued?
A MID is created when a merchant account is issued by your processor or acquirer. MID assignment and deployment works like this:
Where can I find my MID?
Your MID is used to connect a variety of payment-related platforms to your merchant account — your customer relationship management (CRM) or order management system, your gateway, your fraud tools, and your chargeback management solutions.
Because they need to be unique, MIDs are usually a long stream of numbers and letters. So memorizing your MID is probably out of the question! You’ll need to look it up when you need to share it with a new solution provider. Here’s where you can look.
- When your MID is set up, your acquirer or processor will probably give you an official document with all your account information. This is called a VAR sheet, onboarding sheet, MID credential form, tear sheet, or parameter sheet.
- Your MID is probably printed on your monthly processing statements.
- If your merchant account provider has an online portal, you can probably find your MID there.
Can I have multiple MIDs?
Most growing businesses have multiple MIDs.
Why?
Because merchant accounts usually have restrictions. For example, you can sell globally but the majority of your sales have to happen in the U.S. Or you can process in-person transactions or online transactions but not both.
And, multiple accounts means you can optimise your outcomes. For example, some merchant accounts will perform better than others in various regions. So routing transactions to a specific account to enhance approval rates and decrease fees can be a valuable strategy.
So if your business is growing and evolving, you will constantly be adding new merchant accounts to accommodate different situations.
If your business needs more MIDs, let us know. AltoPay offers merchant accounts to expanding businesses that sell locally or globally. Fill out our online form and let us know what you’re looking for.
Can my MID be revoked?
Yes, unfortunately, it is possible to lose a MID once it has been issued.
Technically, you aren’t losing a MID — you’re losing your merchant account and the ability to process payments. When your merchant account is closed, your MID eventually stops existing.
There are several reasons why a merchant account might be closed. We outline those merchant account closure reasons in a different blog article. We encourage you to check it out.
The most common reason for account termination is high fraud, chargeback, and VAMP ratios. Check our chargeback prevention guide to reduce the risk of account closure.
If your MID is revoked, your business may be included in the MATCH List.
What other payments-related IDs are there?
MIDs are one of many unique identifiers that are used throughout the payments ecosystem to route debits and credits to the correct account. And tragically, like MIDs, most identifiers are confusing acronyms!
Here’s a list of other identifiers you might come across as you process payments.
- Terminal IDs are used to identify variables under a specific MID. For card-present transactions, they can be used to identify point-of-sales (POS) terminals. For online transactions, they can be used to identify different product URLs.
- CRM IDs are sometimes used to identify which customer relationship management (CRM) system was used to process a transaction if you have more than one CRM.
- Order IDs are created by your CRM or order management system to identify each order you process.
- ARNs (or acquirer reference numbers) are assigned to each transaction by the acquirer.
BINs (or bank identification numbers) identify financial institutions that function as either an issuer or acquirer. Payment card account numbers incorporate the issuer BIN as the first 4-8 digits. - MCCs (or merchant category codes) are used to describe the goods or services that are sold.
