ABA Number Definition

An ABA number, also known as Routing Transit Number (RTN) or ABA Routing Number, is a nine-digit code assigned by the American Bankers Association to identify each financial institution in the country.

ABA Number Extended Definition
The American Bankers Association introduced ABA Routing Numbers in 1910. All state and federal financial institutions maintaining accounts with the Federal Reserve Bank are eligible for a unique ABA Routing Number.

Automated clearinghouses, electronic funds transfers, and online banking all use routing numbers. You must know your routing number to set up direct deposit, transfer funds, etc.

To find your personal or business routing number, you can:

  • Look at the bottom left of your checks
  • Log in to your banking app
  • Look at your bank statement
  • Call or visit your banking branch

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What Is an ABA Number?
ABA Routing Number

Last Updated By

Rachel Blakely-Gray | Feb 14, 2023

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