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

The ABA number (also called a routing number) is a nine-digit code printed on the bottom left of your checks. It tells other banks and payment systems which financial institution to send money to when you receive a transfer, direct deposit, or automatic payment. Every bank in the United States has its own ABA number — sometimes more than one if the bank operates multiple processing centers.

You need this number whenever someone outside your bank sends you money electronically. Your employer uses it to set up direct deposit. A utility company uses it to pull an automatic payment from your account. Another person uses it to send you money through their bank's online transfer system. Without the correct ABA number, the money goes to the wrong place or the transfer fails.

The ABA number is different from your account number. Your account number identifies your specific account at that bank. The ABA number identifies the bank itself. Together, they form the complete routing information a sender needs.

Key Takeaways

  • An ABA number is a nine-digit code that identifies your bank, printed on the bottom left of your checks.
  • You provide your ABA number and account number together whenever you set up direct deposit, automatic payments, or transfers from another bank.
  • Each bank has at least one ABA number, and large banks may have several depending on where they process payments.
  • If you give the wrong ABA number, the money will go to a different bank or the transfer will fail.

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 will see a series of numbers separated by colons or dashes. The first nine-digit group is your ABA number.

If you do not have checks or prefer not to use them, you can find your ABA number in several other places. Log into your bank's website or mobile app — most banks display it in the account details or settings section. You can also call your bank's customer service line and ask them to read it to you. Some banks print it on statements or deposit slips as well.

If you are unsure whether you have the right number, your bank can confirm it. It is better to ask than to give someone an incorrect number and have a payment fail.

ABA numbers and wire transfers

When you send money to someone at a different bank using a wire transfer, you will need both the ABA number and the account number. A wire transfer moves money directly from one bank to another, usually within one business day. The ABA number tells the sending bank which institution to contact.

Wire transfers are different from ACH transfers (Automated Clearing House transfers), which are slower but cheaper. ACH transfers also use the ABA number, but they process through a clearing house rather than directly between banks. Both types of transfers require you to provide the receiving bank's ABA number.

What happens if you use the wrong ABA number

If you give someone an incorrect ABA number, the transfer will either fail or go to the wrong bank. If it fails, you will usually get a notification that the payment could not be processed, and you can try again with the correct number. If it goes to the wrong bank, the money may end up in someone else's account temporarily, but the receiving bank will eventually catch the error and return it to the sender.

The process of recovering misdirected funds can take several days or weeks. To avoid this, always double-check the ABA number before you give it out. If you are receiving a payment, confirm the number with your bank first. If you are sending a payment, ask the recipient to verify their ABA number matches what you have.

ABA numbers for online banks and credit unions

Online banks and credit unions also have ABA numbers, even though they do not have physical branches. An online bank's ABA number works the same way as a traditional bank's — it identifies the institution for electronic transfers. You can find it the same way: on checks (if the bank issues them), on the bank's website, or by calling customer service.

Credit unions use ABA numbers just like banks do. If you have an account at a credit union, you will need its ABA number for direct deposit and transfers. Some credit unions issue checks with the ABA number printed on them; others require you to look it up online or call.

The difference between ABA numbers and SWIFT codes

If you are sending money to someone outside the United States, you will need a SWIFT code instead of an ABA number. A SWIFT code is an international version of a routing number — it identifies a bank in another country. ABA numbers only work for transfers within the United States.

Some large U.S. banks have both an ABA number (for domestic transfers) and a SWIFT code (for international transfers). If you are receiving money from abroad, ask the sender for your bank's SWIFT code. If you are sending money internationally, your bank will provide the SWIFT code you need.

Frequently Asked Questions

Do I need my ABA number to open a bank account?

No. You need an ABA number only after your account is open and you want to receive transfers or set up automatic payments. When you open an account, the bank assigns you an account number and provides you with the bank's ABA number.

Can two banks have the same ABA number?

No. Each ABA number is unique to one bank or one processing center within a bank. This is how the system ensures money goes to the right place. Large banks may have multiple ABA numbers for different regions or departments, but no two separate banks share the same number.

Is it safe to share my ABA number?

Yes. Your ABA number is public information — it is printed on every check you write. Sharing it alone does not put your account at risk. However, never share your ABA number along with your account number and PIN to anyone you do not trust, as that combination could allow someone to access your account.

What if my bank merged with another bank?

After a merger, your account may keep its original ABA number or be assigned a new one, depending on how the banks consolidate their systems. Your bank will notify you of any changes and provide the new number if needed. Direct deposits and automatic payments set up with the old number may need to be updated.

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

Yes. When you send money to someone, you use their bank's ABA number and their account number. You do not need to know their personal information — just the routing and account numbers. This is why it is safe to ask someone for their ABA number when you need to send them a payment.