The ABA number is your bank's routing number, printed on the bottom left of your checks
The ABA number and the routing number are the same thing. ABA stands for American Bankers Association, the organization that originally assigned these nine-digit codes to every bank and credit union in the United States. When you see a nine-digit number on the bottom left corner of your checks, before your account number, that is your ABA number.
Banks use the ABA number to sort and direct payments. When you set up a direct deposit, send a wire transfer, or arrange an automatic bill payment, the receiving bank uses your ABA number to find your specific bank and branch. Without it, the payment system would not know where to send your money.
The ABA number is not secret and does not need to be protected the way your account number or PIN does. It is printed on every check you write and is public information. Knowing someone's ABA number alone does not let them access your account.
Key Takeaways
- The ABA number is a nine-digit code printed on the bottom left of your checks, before your account number.
- ABA numbers identify your specific bank or credit union and are used to route payments to the correct institution.
- You will need your ABA number when setting up direct deposit, wire transfers, or automatic bill payments.
- The ABA number is public information and does not need to be kept secret like your account number or PIN.
- Different branches of the same bank may have different ABA numbers, so always use the one for your specific branch.
Where to find your ABA number besides your checks
If you do not have a checkbook or cannot locate your checks, your bank's website usually lists the ABA number in the account details section or in the help pages. Log into your online banking account and look for a section labeled "Account Information," "Routing Number," or "Bank Details."
You can also call your bank's customer service line and ask for your routing number. Have your account number ready when you call. The representative will give you the nine-digit ABA number for your specific branch.
The Federal Reserve maintains a public database of ABA numbers. You can search by bank name and state at frbservices.org, though this method is slower than calling your bank directly.
Why different branches sometimes have different ABA numbers
Large banks with many branches may assign different ABA numbers to different locations. This is not universal — some banks use the same ABA number for all branches nationwide — but it happens often enough that you should always use the ABA number for the specific branch where you opened your account.
If you opened your account at a Chase branch in Denver but later moved to a Chase branch in Phoenix, the ABA numbers might be different. Using the wrong one could delay your payment or send it to the wrong location. When in doubt, use the number from your checks or call your current branch to confirm.
ABA numbers for credit unions and online banks
Credit unions have ABA numbers just like traditional banks. If you have a checking account at a credit union, the routing number works the same way. You will find it on your checks or by logging into your credit union's website.
Online banks and fintech companies that offer checking accounts also have ABA numbers assigned by the Federal Reserve. These numbers route payments the same way as any other bank. If you use an online bank, you can find the ABA number on your account page or by calling customer service.
What happens if you use the wrong ABA number
If you provide the wrong ABA number when setting up direct deposit or a wire transfer, the payment may be delayed or sent to the wrong bank entirely. Some payments will bounce back to the sender with an error message. Others might take several days to be returned to you.
For automatic bill payments, using the wrong ABA number could result in the payment not going through at all. Your biller will then contact you about the failed payment. This is why it is important to double-check the number before confirming any transaction.
If a payment has already been sent to the wrong ABA number, contact your bank or the organization that sent the payment as soon as you notice the error. They may be able to recall or redirect it, though this depends on how far the payment has already traveled through the banking system.
ABA numbers and account security
Your ABA number is not sensitive information. It is printed on every check you write and is meant to be shared. Someone who knows your ABA number cannot access your account, withdraw money, or make charges without also having your full account number and other identifying information.
Your account number, on the other hand, should be treated more carefully. Combined with your ABA number, it forms the complete routing and account information needed for transfers. Never share your full account number with someone you do not trust, even if they already know your ABA number.
Frequently Asked Questions
Is the ABA number the same as the routing number?
Yes, they are the same thing. ABA number and routing number are used interchangeably. Both refer to the nine-digit code that identifies your bank or credit union.
Can someone steal money from my account if they know my ABA number?
No. Your ABA number alone is not enough to access or withdraw from your account. A thief would also need your full account number and other identifying information. Treat your ABA number as public, but keep your account number private.
Do I need a different ABA number for each type of account?
No. Your checking account, savings account, and money market account at the same bank all use the same ABA number. The account number changes, but the routing number stays the same.
What if my bank merged with another bank?
After a merger, your ABA number may change or stay the same depending on how the banks consolidated their systems. Your bank will notify you if your routing number changes and will update your account information. Contact your bank to confirm your current ABA number if you are unsure.
Can I use my ABA number to find out how much money is in my account?
No. The ABA number only identifies which bank holds your account. It does not provide access to your balance, transaction history, or any account details. You need to log into your online banking account or call your bank to check your balance.