An ABA number is a nine-digit code that identifies the specific bank or credit union where your account lives

The ABA number (also called a routing number) tells the financial system which institution to send money to. When a government agency, employer, or insurance company needs to deposit a refund directly into your account, they use your ABA number to route that deposit to the correct bank, and then your account number to land it in your specific account. Without the right ABA number, the deposit goes nowhere — or worse, to the wrong bank entirely.

Every bank and credit union in the United States has its own ABA number. If you have accounts at two different banks, each one has a different ABA number. The number is always nine digits long and appears on the bottom left of your checks, if you have them. It is also called a routing number, transit number, or routing transit number (RTN) — all three terms mean the same thing.

For refunds specifically, the ABA number is one of three pieces of information you need to provide for direct deposit: your bank name, your ABA number, and your account number. All three have to match, or the refund will not land in your account.

Key Takeaways

  • An ABA number is a nine-digit code unique to each bank or credit union that tells the financial system where to send your money.
  • You need your ABA number, account number, and bank name together for any direct deposit refund to reach your account.
  • You can find your ABA number on the bottom left of your checks, on your bank's website, or by calling your bank's customer service line.
  • If you provide the wrong ABA number, your refund will be routed to the wrong bank and you will need to contact the sending agency to correct it.

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 find them, you have three other options.

Log into your bank's website or mobile app and look for account details, account information, or routing number. Most banks display this information on the main account page or under a settings or profile section. Some banks label it "routing number" instead of "ABA number," but it is the same thing.

Call your bank's customer service number on the back of your debit card or on your bank statement. Tell them you need your routing number for a direct deposit. They will give it to you in seconds. This is the fastest method if you are on the phone already.

Search the Federal Reserve's routing number database online. You can search by bank name and state, and it will return the ABA number. This works if you know your bank's name but have lost your account information.

Why banks use ABA numbers instead of just bank names

The financial system processes millions of transactions per day. Using a nine-digit code instead of a bank name makes routing faster and eliminates confusion. If you wrote "Bank of America," the system would not know which of the hundreds of Bank of America branches you meant. The ABA number is specific and unambiguous.

The ABA number system was created in 1910 by the American Bankers Association (hence the name ABA). It has been the standard ever since, and it is built into every bank's infrastructure. When you set up direct deposit for a paycheck, a tax refund, or a government payment, the receiving bank's computer system uses your ABA number to identify itself to the sending bank's computer system. The two systems then confirm the account number and complete the transfer.

What happens if you give the wrong ABA number

If you provide an incorrect ABA number, the refund will be routed to a different bank. Depending on what happens next, you may or may not recover the money quickly.

If the wrong bank receives the deposit and the account number does not exist at that bank, the deposit will usually bounce back to the sending agency within one to three business days. The agency will then contact you to ask for the correct information. You can provide the correct ABA number and account number, and they will re-send the refund. This adds one to two weeks to your timeline.

If the wrong ABA number happens to route to a real account at a different bank — even if the account number does not match — the deposit may sit in a suspense account or be returned more slowly. Contact the sending agency immediately with your correct information. Do not wait for the money to bounce back on its own.

To avoid this problem, double-check your ABA number and account number before you submit them. Verify them against your checks, your bank's website, or a call to your bank. A few seconds of checking now saves weeks of waiting later.

ABA numbers for different types of accounts and institutions

Your ABA number is the same whether you have a checking account, savings account, or money market account at the same bank. The ABA number identifies the bank, not the account type. Your account number is what distinguishes one account from another within that bank.

Credit unions also have ABA numbers. If your refund is going to a credit union account, you will need that credit union's ABA number, not a bank's. Credit union ABA numbers work exactly the same way as bank ABA numbers — they are nine digits and route money to the correct institution.

Some online banks and financial technology companies also have ABA numbers. If you use an online-only bank or a fintech account, your statement or account information page will show your ABA number. The process is identical to a traditional bank.

Confirming your ABA number matches your bank

Before you submit your banking information for a refund, take 30 seconds to confirm that your ABA number matches your bank. Search your bank's name plus "ABA number" or "routing number" on the bank's website. Most banks have a page that lists this information for each location or for the entire institution.

If you are unsure whether the number you found is correct, call your bank directly. Do not rely on a third-party website unless it is the Federal Reserve's official routing number database. Some websites display outdated or incorrect information, and you do not want to discover that after your refund has been sent.

For tax refunds, the IRS and state tax agencies will ask you to confirm your routing number and account number before they process your direct deposit. Read the confirmation screen carefully. If something looks wrong, correct it before you submit. Once the refund is sent, changing the banking information requires contacting the agency and waiting for a reissue.

Frequently Asked Questions

Is my ABA number the same as my account number?

No. Your ABA number identifies your bank; your account number identifies your specific account within that bank. You need both for direct deposit. The ABA number is nine digits and appears on the left side of your checks. Your account number is usually 10 to 12 digits and appears in the middle or right side of your checks.

Can I use the same ABA number for multiple accounts at the same bank?

Yes. If you have a checking account and a savings account at the same bank, they share the same ABA number. The account number is what tells the system which account to deposit into. Make sure you provide the correct account number for whichever account you want the refund to go to.

What if my bank merged with another bank?

Your ABA number may have changed. Contact your bank or check your most recent statement to confirm. If you provided an old ABA number to a refund program before the merger, contact that program to update your banking information. Do not assume your old number still works.

Do I need an ABA number if I want a check mailed instead of direct deposit?

No. If you choose to receive your refund by check, you only need to provide your mailing address. ABA numbers are only for direct deposit. Some refund programs offer both options; choose whichever works best for you.