An ABA number is your bank's routing number — a nine-digit code that tells the financial system where to send money when you receive a transfer or pay a bill by check.
The term "ABA number" and "routing number" mean the same thing. ABA stands for American Bankers Association, the organization that created the system. You'll see both names used interchangeably, though routing number is more common today.
Think of it this way: your account number identifies you at your bank. Your ABA number identifies your bank itself in the national banking network. When someone sends you money electronically or you write a check, the ABA number is what directs that money to the right bank, and your account number directs it to the right account within that bank.
Key Takeaways
- An ABA number is a nine-digit code that identifies your specific bank or credit union in the U.S. banking system.
- You need your ABA number whenever you set up direct deposit, make an electronic transfer, or receive a wire transfer.
- Your ABA number is printed on the bottom left of your checks, and you can also find it on your bank's website or by calling customer service.
- Different branches of the same bank may have different ABA numbers, so always use the code for the branch where your account is held.
- ABA numbers are public information — sharing yours does not put your account at risk because someone also needs your account number to access funds.
Where to find your ABA number
The easiest place to find your ABA number is on a check from your account. Look at the bottom left corner. You'll see nine digits printed there — that's your ABA number. The middle set of numbers (usually eight digits) is your account number.
If you don't have checks handy, log into your online banking and look for account details or account information. Most banks display the ABA number there. You can also call your bank's customer service line and ask for your routing number — they'll give it to you in seconds.
Some banks print the ABA number on statements or debit cards, though not all do. If you're having trouble locating it, your bank's website usually has a "routing number" or "ABA number" lookup tool where you can enter your state and branch location.
Why banks use ABA numbers instead of just account numbers
The U.S. banking system moves trillions of dollars every year between thousands of different banks, credit unions, and financial institutions. Without a standardized way to identify each bank, transfers would get lost or sent to the wrong place constantly.
The ABA number system, created in 1910, solved this problem by giving every bank a unique identifier. When you set up direct deposit at a new job, for example, your employer's payroll system uses your ABA number to find your bank, then uses your account number to find your specific account. The same process happens for bill payments, wire transfers, and ACH transfers (electronic transfers between accounts).
This two-part system — ABA number plus account number — is what makes modern banking possible. It's the reason money can move between banks when ready and reliably.
ABA numbers for different branches and account types
If your bank has multiple branches, each branch may have its own ABA number. This matters because you need to use the ABA number for the specific branch where your account is held, not just any branch of that bank.
For example, if you opened your account at a Chase branch in Denver, you use that branch's ABA number — not the ABA number for a Chase branch in Chicago. Your checks will print with the correct ABA number automatically, but if you're entering it manually (like setting up direct deposit online), double-check that you're using the right one.
The type of account you have — checking, savings, money market — doesn't change your ABA number. One ABA number covers all account types at that branch.
What information is safe to share
Your ABA number is public information. Sharing it does not put your account at risk because it only identifies your bank, not your specific account. Think of it like sharing your street address — it tells someone where you live, but they still need your house key to get inside.
To actually move money from your account, someone would need both your ABA number and your account number. Even with both, most transfers require additional verification like a password or a one-time code sent to your phone.
That said, there's no reason to share your ABA number with anyone except when you're setting up a legitimate transaction like direct deposit or a bill payment. If someone asks for it unsolicited, it's fine to ask why they need it before you provide it.
Common situations where you'll need your ABA number
Direct deposit is the most common reason you'll need your ABA number. When you start a new job, your employer asks for it so payroll can deposit your check into the right account at the right bank.
You'll also need it to set up automatic bill payments through your bank's website, to receive a wire transfer from another bank, or to transfer money between your own accounts at different banks. If you're moving money to a family member's account or receiving a payment from someone, you'll provide your ABA number along with your account number.
Some online services like PayPal or Venmo ask for your ABA number and account number if you want to link your bank account to their platform. This is normal and safe as long as you're using the official app or website.
What happens if you use the wrong ABA number
If you accidentally use the wrong ABA number when setting up a transfer, the money will go to the wrong bank. The sending bank will eventually catch the error and return the money to the sender, but this can take several days or even weeks.
If you realize you've made a mistake before the transfer goes through, contact your bank when ready and ask them to cancel it. If the transfer has already been sent, contact your bank and ask them to initiate a recall. They can't always get the money back, but they can try.
To avoid this problem, always double-check your ABA number before confirming a transfer, especially if you're entering it manually rather than selecting your bank from a dropdown menu.
Frequently Asked Questions
Is my ABA number the same as my routing number?
Yes, they're the same thing. ABA number and routing number are two names for the same nine-digit code. Routing number is the more common term today, but banks and older documents often still use ABA number.
Can someone withdraw money from my account if they have my ABA number?
No. Your ABA number only identifies your bank, not your specific account. Someone would need both your ABA number and your account number to attempt a transfer, and most banks require additional verification like a password or security code before allowing any withdrawal.
Do I need a different ABA number for my savings account and checking account?
No. Both accounts at the same branch use the same ABA number. The account number is what distinguishes between your checking and savings accounts.
What if I bank at a credit union instead of a bank?
Credit unions also have routing numbers (ABA numbers). The process is identical — you'll find it on your checks or through your credit union's website. Credit unions participate in the same national system as banks.
Does my ABA number change if I move to a different branch?
It depends on your bank's structure. Some banks assign one ABA number to all branches in a region, while others give each branch its own number. If you move your account to a different branch, ask your bank whether your ABA number changes. If it does, update any automatic payments or direct deposits that use the old number.