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 where to send money when you receive a transfer or pay a bill. Every bank in the United States has one. When you set up direct deposit at work, pay a bill by bank transfer, or send money to someone else's account, you provide your ABA number so the money reaches the right institution.

ABA stands for American Bankers Association, the organization that originally assigned these codes. The number is not secret — it appears on the bottom left of every check you write, and you can find it on your bank's website or by calling customer service. It is different from your account number, which identifies your specific account within that bank.

The ABA number matters because money moves through a network of banks, and each transfer needs to know which bank to contact. Without it, a payment could get lost or sent to the wrong place. If you give an incorrect ABA number, the transfer may bounce back or be delayed while the banking system tries to sort out where it should go.

Key Takeaways

  • An ABA number is a nine-digit code that identifies your bank, not your individual account.
  • You need your ABA number to set up direct deposit, pay bills by bank transfer, and receive wire transfers.
  • The ABA number appears on the bottom left of your checks and is available on your bank's website or by phone.
  • Each bank has only one ABA number, even if it has multiple branches, so the number is the same whether you bank in-person or online.
  • Providing an incorrect ABA number can cause transfers to fail or be delayed, so double-check before submitting payment information.

Where to find your ABA number

The easiest place to find your ABA number is on a check. Look at the bottom left corner — the first set of nine digits is your ABA number. The second set of numbers is your account number, and the third set is the check number.

If you do not have checks or prefer not to look them up, log into your bank's website or mobile app. Most banks display the routing number in the account details section, often labeled "routing number" or "ABA number." You can also call your bank's customer service line and ask for the routing number — they will give it to you over the phone.

Some banks have different ABA numbers depending on which service you are using (for example, wire transfers versus ACH transfers), though this is uncommon. If you are setting up a specific type of transfer, ask your bank whether the ABA number changes based on the transfer method.

When you need to provide your ABA number

You provide your ABA number whenever money needs to move into your account from an outside source. The most common situations are direct deposit from your employer, automatic bill payments from your bank account, and wire transfers from another person or business.

If someone is sending you money through a peer-to-peer app like Venmo or PayPal, you usually do not need your ABA number — those apps link to your account differently. But if they are sending money directly from their bank account to yours, or if you are setting up an automatic payment to a creditor or utility company, you will need both your ABA number and your account number.

You also need your ABA number if you are moving money between your own accounts at different banks, or if you are receiving a tax refund and want it deposited directly into your account instead of receiving a check.

ABA numbers and ACH transfers

ACH stands for Automated Clearing House, the system that handles most routine bank-to-bank transfers in the United States. When you set up direct deposit or an automatic bill payment, that money moves through the ACH network using your ABA number and account number.

ACH transfers typically take one to three business days to complete. The ABA number tells the ACH system which bank to contact, and the account number tells that bank which account within the bank should receive the money. If either number is wrong, the transfer fails and the money bounces back to the sender.

ACH transfers are different from wire transfers, which move money faster (usually same-day or next-day) but may use a different routing number. Wire transfers also cost money, while ACH transfers are usually free. Ask your bank whether the ABA number is the same for both types of transfers before you set one up.

What happens if you provide the wrong ABA number

If you give an incorrect ABA number, the transfer will usually fail and bounce back to the sender within one to three business days. The sender's bank will reject the payment because the ABA number does not match any real bank in the system, or it matches a different bank than the account number suggests.

In rare cases, an incorrect ABA number might send the money to a different bank, where it sits in a suspense account until someone notices the error. This can take weeks to sort out. The safest approach is to double-check your ABA number before submitting any payment information, especially for large transfers or recurring payments.

If a transfer fails, contact your bank to confirm you have the correct ABA number. Your bank can also help you trace a transfer that went to the wrong place and work with the other bank to recover it.

ABA numbers for online banks and credit unions

Online banks and credit unions have ABA numbers just like traditional banks do. If you bank with an online institution like Ally, Charles Schwab, or a local credit union, you can find your ABA number the same way — on a check, on the website, or by calling customer service.

Some online banks do not issue checks, so you may need to log into your account or call to find the number. Credit unions often have their own routing numbers separate from any bank they are affiliated with, so make sure you are using your credit union's number, not a partner bank's number.

The process for using the ABA number is identical whether you bank online or in person — you provide it whenever you need money to move into your account from an outside source.

Frequently Asked Questions

Is my ABA number the same at every branch of my bank?

Yes. Your bank has one ABA number for the entire institution, regardless of how many branches it operates. Whether you opened your account at a branch downtown or online, the routing number is the same. You do not need to look up a different number based on which branch you use.

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

No. Your ABA number alone is not enough to access your account or move money out. A person would also need your account number and usually additional verification. Your ABA number is public information — it appears on every check you write — so sharing it is safe.

Do I need my ABA number to receive a wire transfer?

Yes, and sometimes you need a different routing number for wire transfers than for ACH transfers. Ask your bank for the wire transfer routing number specifically, as it may differ from the standard ABA number. Provide both the wire routing number and your account number to the person sending the wire.

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

Usually not immediately. Your ABA number may stay the same for months or years after a merger, or your bank may assign you a new one. If your bank merges, contact customer service to confirm whether your routing number has changed, especially if you have automatic payments set up.

Can I use someone else's ABA number to send them money?

Yes. If you are sending money to someone else's account, you need their ABA number (their bank's routing number) and their account number. You do not need their permission to have this information — it is public. The money will go to their account at their bank.