Your bank's ABA number is a nine-digit code that identifies which bank holds your account
The ABA number (also called a routing number) tells the financial system which bank to send money to when you receive a transfer. It is not unique to your account — every customer at the same bank branch shares the same ABA number. Think of it as your bank's address in the payment system.
You will see the ABA number printed on the bottom left of your checks. If you do not have checks, your bank can tell you the number in seconds, or you can find it on your bank's website or in your online banking portal. The number matters because without it, a wire transfer or ACH payment (the electronic transfers that move most money between accounts) cannot reach you.
The ABA number is different from your account number. Your account number identifies your specific account at that bank. Together — ABA number plus account number — they form the routing information a sender needs to move money into your account.
Key Takeaways
- The ABA number is a nine-digit code that identifies your bank, not your individual account.
- You need both your ABA number and your account number for someone to send you a wire transfer or ACH payment.
- The ABA number appears on the bottom left of your checks and is also available from your bank's website or customer service.
- Different branches of the same bank may have different ABA numbers, so always confirm you have the correct one for your specific branch.
Where to find your ABA number
The easiest place to look is the bottom left corner of any check you have. The first nine digits printed there are your ABA number. If you do not have checks or cannot locate them, log into your online banking account — most banks display the routing number on the account details page or in a section labeled "Account Information" or "Wire Transfer Details."
You can also call your bank's customer service line or visit a branch in person. Have your account number ready when you call, so the representative can confirm they are giving you the routing number for the correct branch. Some banks operate multiple branches with different ABA numbers, so it matters that you get the right one.
The Federal Reserve maintains a public database of ABA numbers, but using it requires knowing your bank's name and state. For speed, your bank itself is the most reliable source.
Why banks use ABA numbers in the payment system
When money moves electronically between banks, the payment system needs to know exactly where to send it. The ABA number is part of the infrastructure that makes this possible. Without it, a transfer instruction would be like mailing a letter with only a name and no address — the postal service would not know where to deliver it.
The ABA system was created in 1910 by the American Bankers Association (which is where the acronym comes from). It became the standard way for banks to identify each other in the United States. Today, every bank that participates in the ACH network, the wire transfer system, or other electronic payment channels has an ABA number.
The number encodes information about the bank's location and Federal Reserve district, though you do not need to decode it yourself — you just need to provide it when requested.
ABA numbers versus account numbers
These two numbers work together but serve different purposes. Your ABA number identifies the bank. Your account number identifies your specific account within that bank. When you give someone your banking information for a transfer, you are giving them both.
If you share only your ABA number, the sender cannot complete a transfer — they would not know which account at that bank to send the money to. If you share only your account number, the sender would not know which bank to contact. Both pieces are required.
Your account number is typically 8 to 12 digits long and also appears on the bottom of your checks, to the right of the ABA number. It is printed on your bank statements and visible in your online banking portal.
When you need to provide your ABA number
You will need your ABA number when setting up direct deposit for payroll or benefits, arranging a wire transfer into your account, setting up automatic bill payments from your bank account, or linking your bank account to a third-party payment service like PayPal or Venmo.
You may also need it if you are receiving a transfer from someone else — they will ask you for it so they can send the money to the correct bank. Some employers ask for it before they can set up your paycheck deposit. Landlords sometimes request it if you are paying rent by automatic transfer.
In general, any time money needs to move electronically into or out of your account, the ABA number is part of what makes that possible.
What happens if you give the wrong ABA number
If you provide an incorrect ABA number, the transfer will usually be rejected before it leaves the sender's bank. The payment system will recognize that the ABA number does not match any bank in the network, and the transaction will fail. The money stays in the sender's account, and they will be notified that the transfer could not go through.
In rare cases, a transfer might go to a different bank than intended if the ABA number you provided belongs to a real bank but not your bank. This is less common because most senders will catch the error when they see the bank name does not match what they expected. If money does go to the wrong bank, the sender's bank can usually reverse the transaction, though it may take several business days.
The safest approach is to double-check your ABA number before giving it to anyone. Confirm it with your bank directly rather than relying on memory or an old document.
ABA numbers for different types of accounts
The ABA number is the same regardless of whether you have a checking account, savings account, money market account, or any other type of deposit account at that bank. What changes is your account number — each account you hold has its own unique account number.
If you have multiple accounts at the same bank branch, they all share the same ABA number but have different account numbers. If you have accounts at different branches of the same bank, they may have different ABA numbers depending on how the bank structures its routing system.
Credit unions also use ABA numbers, and the process works the same way. Your credit union will have an ABA number, and you will need it along with your account number to receive transfers.
Frequently Asked Questions
Can I use the same ABA number for all my accounts at one bank?
Yes, if all your accounts are at the same branch. Each account has its own account number, but they share the ABA number. If you have accounts at different branches, check with your bank — some banks assign different ABA numbers to different branches.
Is my ABA number the same as my bank's SWIFT code?
No. The ABA number is used for domestic transfers within the United States. A SWIFT code is used for international wire transfers. If you are sending or receiving money from outside the US, you will need the SWIFT code instead.
What if my bank merged with another bank?
Your ABA number may change after a merger, depending on how the banks consolidate their systems. Your bank will notify you if this happens and will update your information. Always confirm your current ABA number with your bank if you have not used it in a while.
Do I need to memorize my ABA number?
No. You can look it up whenever you need it. Most people keep it written down or saved in a note on their phone for quick reference, but memorizing it is not necessary.