“ABA” stands for the American Bankers Association, the organization that founded the ABA routing number system in 1910. ABA routing numbers are unique nine-digit codes that financial institutions in the United States use to identify specific banks or credit unions. They’re used to process financial transactions such as direct deposits, electronic funds transfers, wire transfers, and check processing; they ensure that these transactions are sent to the correct institution and branch.

This guide will cover what ABA routing numbers are, how these numbers are used, and how to locate your own.

What’s in this article?

• How are ABA routing numbers used?
  
• How to find your routing number
  
• Difference between a routing number and an account number
  

How are ABA routing numbers used?

According to the ABA, there are approximately 28,000 active routing numbers in the US. ABA routing numbers are used by banks and other financial institutions to process the following types of financial transactions:

• Direct deposits: Employers, government agencies, and other entities use ABA routing numbers to send payments such as paychecks, tax refunds, or Social Security benefits directly to individuals’ bank accounts.

• Electronic funds transfers (EFTs): Banks use ABA routing numbers to electronically transfer funds between accounts for purposes such as automatic bill payments or person-to-person (P2P) transfers.

• Wire transfers: Banks and credit unions use ABA routing numbers to ensure funds sent via wire transfer go to the correct institution.

• Checks: Financial institutions use ABA routing numbers to process checks to their correct destination. ABA routing numbers are listed on the bottom of all checks.

• Automated Clearing House (ACH) transactions: ACH payments—which cover a wide range of electronic transactions including bank debits and credits, business-to-business (B2B) payments, and payroll processing—also require ABA routing numbers.

How to find your routing number

If you have multiple accounts at a single bank, each might use the same routing number. But if you have accounts at different banks or different branches, the routing numbers could vary.

Here are a few places you can look to find your routing number:

• Checks: The routing number is a nine-digit string printed on the bottom left corner of your checks. It’ll be the first set of numbers you see, followed by your account number and the check number.

• Bank statements: Many banks also include the routing number on your monthly bank statements. It might be located in the upper right corner or somewhere within the details of your account information.

• Bank’s online portal or mobile app: Most banks allow you to view your routing number directly through their online banking platform or mobile app. Look for a section on account details or routing numbers.

If you’re unable to find your routing number through the methods mentioned above, you can always contact your bank directly. A customer service representative can provide you with your routing number over the phone or through a secure online chat.

Difference between a routing number and an account number

Routing number

An ABA routing number identifies a specific financial institution or bank branch. It directs financial transactions to the correct bank during processing.

• Structure: A nine-digit code used in the United States.

• Usage: Used for tasks such as direct deposits, wire transfers, electronic funds transfers, and check processing.

• Location: Found at the bottom left corner of a check or provided by the bank for other transactions.

Account number

A bank account number identifies an individual account within a financial institution. It’s unique to each account within a bank or credit union.

• Structure: Varies in length and format but is usually longer than a routing number.

• Usage: Directs funds to a specific account during a transaction. It’s needed for direct deposits, electronic funds transfers, wire transfers, and other banking operations.

• Location: Found on checks, bank statements, and other bank-related documents. On a check, it’s located between the routing number and the check number and is often separated from the routing number by a space or symbol.