An ABA number is a nine-digit code that identifies which bank holds your account

The ABA number (also called a routing number) tells the banking system which specific bank to send money to when you make a transfer. It is not tied to your individual account — it identifies the bank itself. Every bank in the United States has one ABA number, and that number stays the same whether you have a checking account, savings account, or both.

The name comes from the American Bankers Association, the organization that originally assigned these codes in the 1910s. Today the Federal Reserve maintains the system. When you wire money, set up direct deposit, or authorize an automatic payment, you will need to provide both your ABA number and your account number so the money reaches the right place.

Key Takeaways

  • An ABA number is a nine-digit code that identifies your bank, not your individual account.
  • You need your ABA number whenever you set up direct deposit, wire money, or authorize automatic bill payments.
  • You can find your ABA number on the bottom left of your checks, on your bank's website, or by calling your bank.
  • Different branches of the same bank usually share one ABA number, though some large banks have multiple routing numbers.
  • Providing an incorrect ABA number will cause a transfer to fail or go to the wrong bank, but the money can usually be recovered.

Where to find your ABA number

The easiest place to look is the bottom left corner of your checks. The first nine digits printed there are your ABA number. If you do not have checks or prefer not to look at them, log into your bank's website or mobile app — most banks display the routing number in the account details or transfer settings section.

You can also call your bank's customer service line and ask for your routing number. Have your account number ready when you call. Some banks print the routing number on statements or deposit slips as well, though this varies by institution.

When you need to provide your ABA number

You will need your ABA number in several common situations. The most frequent is setting up direct deposit — your employer or a government agency uses it to deposit your paycheck or benefits directly into your account. You also need it when you authorize automatic bill payments through your bank or a biller's website.

If you are sending or receiving a wire transfer, both the sending and receiving banks require ABA numbers. The same applies when you set up ACH transfers (automated clearing house transfers) to move money between your own accounts at different banks or to send money to someone else's account. Some peer-to-peer payment services also ask for it, though many now use account numbers alone.

What happens if you give the wrong ABA number

If you provide an incorrect ABA number, the transfer will either fail before it leaves your bank, or it will reach a different bank than intended. In either case, the money does not disappear — it either stays in your account or goes to the wrong institution, where it can be traced and returned.

If money reaches the wrong bank, contact your bank immediately with the transfer details (date, amount, and the incorrect routing number). Your bank can file a trace to locate the funds and request they be sent back. This process usually takes five to ten business days. If the money went to another customer's account at the wrong bank, that bank will contact the account holder and ask them to return it. Do not assume the transfer is lost — the banking system has procedures to recover misdirected funds.

ABA numbers and bank branches

Most banks use a single ABA number for all their branches nationwide. If you move to a different state or switch to a different branch of the same bank, your ABA number stays the same. This is true for most regional and national banks.

Some very large banks or banks with complex structures have multiple ABA numbers — one for each major division or region. If you are unsure whether your branch has its own routing number, ask your bank directly or check the bottom of your checks. The number printed there is the correct one for your specific account.

ABA numbers versus account numbers

An ABA number and an account number serve different purposes and are not interchangeable. The ABA number identifies the bank. Your account number identifies your specific account within that bank. Together, they tell the banking system exactly where to send money.

Think of it this way: the ABA number is like the address of a post office, and your account number is like your mailbox inside it. You need both pieces of information for any transfer to work correctly. If someone asks for your routing number, they are asking for your ABA number. If they ask for your account number, that is a separate nine- to twelve-digit code unique to your account.

Security and sharing your ABA number

Your ABA number is public information — it is printed on every check you write and is not considered sensitive on its own. You can safely share it with employers, billers, and anyone else who needs to send money to your account. Sharing your ABA number alone does not put your account at risk.

However, do not share your ABA number along with your account number and other personal details to someone you do not trust. A scammer with both numbers could potentially set up unauthorized transfers or payments from your account. If you are unsure whether a request for your routing number is legitimate, contact your bank directly using the phone number on your statement or card — never use a number provided by the person asking.

Frequently Asked Questions

Is my ABA number the same as my bank's SWIFT code?

No. Your ABA number is used for domestic transfers within the United States. A SWIFT code is used for international wire transfers and is different. If you are sending money outside the US, you will need the recipient's SWIFT code, not their ABA number.

Can I have more than one ABA number if I have accounts at multiple banks?

Yes. Each bank has its own ABA number. If you have a checking account at Bank A and a savings account at Bank B, you will have two different ABA numbers — one for each bank. Your account numbers will also be different.

What if my bank merged with another bank — does my ABA number change?

Usually not immediately. When banks merge, the routing numbers often stay the same for existing customers for a period of time to avoid disrupting direct deposits and automatic payments. Your bank will notify you if your ABA number changes, and you should update any automatic payments or direct deposits. Check your statements or call your bank if you are unsure.

Do credit unions have ABA numbers?

Yes. Credit unions are part of the same banking system and have routing numbers just like banks do. The process for finding and using your credit union's routing number is identical to a bank's.

Can someone steal money from my account if they only have my ABA number?

Not with just the ABA number alone. They would also need your account number and typically some form of authorization or verification. If you are concerned about unauthorized activity, monitor your account regularly and contact your bank immediately if you see transfers you did not make.