A merchant ID number—commonly called a merchant number or MID—is a 15-digit numerical identifier used to facilitate credit and debit card payments for your business. It’s an important part of the process that moves your customers’ payments from their accounts to yours. Below we’ll explain why you need a merchant ID number, how to get one, how to find yours, and what having one means for your business.

What’s in this article?

• How merchant ID numbers work
  
• Why your business needs a merchant ID
  
• Merchant ID lookup: How to find your MID
  
• How to get a merchant ID number
  
• Can you have more than one merchant ID?
  
• Can you lose your merchant ID?
  
• How Stripe Payments can help
  

How merchant ID numbers work

MIDs are used to identify your merchant account. When the customer submits their payment information at the point of sale and the transaction process begins, the MID ensures the merchant account is marked as the destination for the funds. As the transaction is processed, the customer’s payment information travels alongside the MID as all the key stakeholders—the merchant acquirer, the card issuer, and the payment processor—communicate with each other about the transaction. Like the mailing address on an envelope, your MID tells the funds where to go.

Why your business needs a merchant ID

Your business needs a merchant ID number so that your customers’ card payments can travel from their bank accounts to your bank account. Without a merchant ID number, you couldn’t receive those funds.

Whether you see that number depends on which payment-processing provider you use and which financial institution hosts your merchant account.

Stripe users, for example, don’t see or deal with their merchant ID number directly. Since Stripe is a full-service payment-processing solution that offers the functionality of a merchant account, our users don’t need to open a merchant account on their own and therefore are not given a merchant ID number.

Using the mail metaphor again, all customer payments are sent to Stripe’s main mailing address, and Stripe then routes each payment to the correct business. Stripe users can avoid connecting separate components to create a payment ecosystem.

Merchant IDs are also separate from merchant account numbers, which serve as the underlying and backend address where funds are deposited. Along with a merchant ID, your acquiring bank or payment processor will also assign you a merchant category code, which is a four-digit number based on your business’s primary types of goods or services.

Merchant ID lookup: How to find your MID

There is no public database where you can look up your merchant ID number. This is a basic security measure, similar to how your personal bank doesn’t publish a list of customer account numbers.

But finding your merchant ID is usually very simple. Here are a few ways to do so:

• Check your merchant account statement: In most cases, this is the first place you should go to locate your merchant ID number. Look for a 15-digit number on the upper right corner of your merchant account statement—that’s your MID.

• Check your payment terminal: Some terminals have the MID listed on them, usually on the side or bottom of the machine.

• Call your merchant account provider: If you’re having a difficult time locating your merchant ID, you can always call your merchant account provider and ask for the information.

• Check your bank statement: While your merchant account statement will definitely display your MID, your regular business bank account statement might list it in a different form. When you look at transactions from your merchant account, you might be able to find your MID displayed in the description. Note: The number displayed on the statement might be a partial MID and not the full 15-digit identifier, so confirm with another source if you’re unsure.

Again, because Stripe provides merchant account functionality, Stripe users will have an overall account ID that identifies their Stripe account, but not an actual merchant ID.

How to get a merchant ID number

Your payment processor or acquiring bank will assign you a merchant ID when you open an account. The requirements to obtain an MID are the same as the requirements to open a merchant account. You’ll need to go through the verification process, which includes providing materials such as your employer identification number (EIN) and other proof that your business is registered and legally ready to operate.

Can you have more than one merchant ID?

While it’s possible to have more than one MID, for the vast majority of businesses, one is enough. However, if you own multiple unique businesses that have separate merchant accounts, then you’ll have separate MIDs for each one.

One scenario in which a single business might have multiple merchant IDs is if your business contains multiple, distinct revenue sources, and you want to keep different streams of funds in separate accounts for simplicity. For example, if you run an independent movie theater that has a café within it, you might choose to keep separate merchant accounts—and merchant IDs—for the theater and the café, even though they are part of the same business.

Can you lose your merchant ID?

Yes, it’s possible to have your merchant ID revoked. The most common reason for merchants to lose their merchant ID is having too many chargebacks. Additionally, publicly exposing your merchant ID can open your business to further risks like account takeovers, unauthorized processing, and fraud. If you decide to switch merchant service providers, you will also relinquish your old MID and be assigned a new one by your new provider.

How Stripe Payments can help

Stripe Payments provides a unified, global payments solution that helps any business—from scaling startups to global enterprises—accept payments online, in person, and around the world.

Stripe Payments can help you:

• Optimize your checkout experience: Create a frictionless customer experience and save thousands of engineering hours with prebuilt payment UIs, access to 125+ payment methods, and Link, a wallet built by Stripe.
  
• Expand to new markets faster: Reach customers worldwide and reduce the complexity and cost of multicurrency management with cross-border payment options, available in 195 countries across 135+ currencies.
  
• Unify payments in person and online: Build a unified commerce experience across online and in-person channels to personalize interactions, reward loyalty, and grow revenue.
  
• Improve payments performance: Increase revenue with a range of customizable, easy-to-configure payment tools, including no-code fraud protection and advanced capabilities to improve authorization rates.
  
• Move faster with a flexible, reliable platform for growth: Build on a platform designed to scale with you, with 99.999% historical uptime and industry-leading reliability.
  

Learn more about how Stripe Payments can power your online and in-person payments, or get started today.