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 financial system which specific bank to send money to when you receive a transfer. It is not tied to your individual account — it identifies the bank itself. Every bank in the United States has one, and many banks have more than one if they operate multiple branches or processing centers.
The name comes from the American Bankers Association, the organization that originally created the system in 1910. Today, the Federal Reserve maintains the official registry of all ABA numbers in the country.
You need your ABA number whenever money moves into your account from outside sources: direct deposit from an employer, a wire transfer from another person, an ACH payment from a bill you are paying, or a refund from the government. Without the correct ABA number, the money goes to the wrong bank and the transfer fails or gets delayed.
Key Takeaways
- An ABA number is a nine-digit code that identifies your bank, not your individual account.
- You need your ABA number and account number together to receive transfers, direct deposits, and ACH payments.
- Your ABA number appears on the bottom left of your checks, in your online banking portal, or by calling your bank.
- Different branches of the same bank may have different ABA numbers, so always confirm you have the right one for the specific branch where your account is held.
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 — the first nine digits are your ABA number. The next set of digits is your account number.
If you do not have checks, log into your online banking portal. Most banks display the ABA number in the account details section, sometimes labeled "routing number" or "bank routing number." You can also call your bank's customer service line and ask for your ABA number — they will give it to you immediately.
Some banks print the ABA number on your debit card or in your account statements, though not all do. If you cannot find it anywhere, a phone call to your bank is the fastest route.
ABA numbers versus account numbers
These two numbers work together but do different jobs. Your ABA number identifies the bank. Your account number identifies your specific account within that bank. You need both to receive money.
Think of it like an address: the ABA number is the city and state, and your account number is the street address and apartment number. The ABA number gets the money to the right bank; the account number gets it to the right account once it arrives.
If you give someone only your ABA number, they cannot send you money — they need your account number too. If you give them only your account number, they cannot send you money either — they need to know which bank to send it to.
When you need to provide your ABA number
You provide your ABA number and account number together in these situations: setting up direct deposit with an employer, arranging automatic bill payments, requesting a wire transfer, filing taxes and expecting a refund, or receiving a payment from a government program.
You do not need your ABA number for debit card purchases, credit card payments, or checks you write to someone else. You also do not need it to send money out of your account — you need it only when money is coming in.
Some online payment services (like PayPal or Venmo) ask for your bank's ABA number and your account number if you want to link your bank account to their platform. This lets them pull money from your account when you authorize a transfer.
What happens if you give the wrong ABA number
If you provide an incorrect ABA number, the transfer usually fails and bounces back to the sender within one to three business days. The money does not arrive in your account, and the sender is notified that the routing number was invalid.
Sometimes a transfer goes to a different bank by mistake if the ABA number is wrong but still valid (because it belongs to a real bank). In that case, the receiving bank will reject it because the account number does not exist in their system, and it bounces back the same way.
The key is to double-check your ABA number before you give it out. If a transfer fails, ask the sender to confirm they used the correct ABA number for your specific branch. Some banks have multiple ABA numbers, and using the wrong one for your branch will cause the transfer to fail.
ABA numbers and multiple branches
Large banks often have different ABA numbers for different branches or processing centers. This means two branches of the same bank may have different routing numbers. If you move your account to a different branch or open an account at a different location, your ABA number might change.
Before you set up direct deposit or automatic payments, confirm that you have the ABA number for the specific branch where your account is held. If you are unsure, call that branch directly or check your most recent statement — it should show the ABA number associated with your account.
If you switch branches and forget to update your ABA number with your employer or a service that pulls money from your account, transfers may fail or go to the wrong place. Update it as soon as you move your account.
ABA numbers and wire transfers
Wire transfers require your ABA number, account number, and sometimes additional information depending on the type of wire. For a domestic wire (money staying within the United States), you need the recipient's ABA number, account number, and full name.
For an international wire, you may also need a SWIFT code (which identifies the bank internationally) in addition to the ABA number. Some banks use SWIFT codes instead of ABA numbers for international transfers, so ask the receiving bank which code they need.
Wire transfers are faster than ACH transfers but also more expensive and harder to reverse if something goes wrong. Always confirm the ABA number and account number before you send a wire, because once it leaves your bank, recovery is difficult.
Frequently Asked Questions
Is my ABA number the same as my bank's SWIFT code?
No. Your ABA number is used for transfers within the United States. A SWIFT code is used for international transfers and identifies your bank globally. Some banks provide both, but they are different codes for different purposes.
Can someone steal money from my account if they know my ABA number?
Not with just your ABA number alone. They would also need your account number, and even then they cannot withdraw money — they can only initiate a transfer into your account. Your ABA number is safe to share; it is public information printed on your checks.
Do I need a different ABA number for savings and checking accounts?
No. Both your savings and checking accounts at the same bank use the same ABA number. The account number is what distinguishes between them. When you provide your ABA number and account number together, the bank knows which account to deposit into.
What if my bank merged with another bank — does my ABA number change?
Sometimes. When banks merge, the surviving bank may keep both ABA numbers for a transition period, or it may consolidate accounts under one routing number. Contact your bank to learn about your ABA number changed after a merger, and update it with your employer and any services that pull money from your account.
Can I look up someone else's ABA number?
Yes. The Federal Reserve publishes a searchable database of ABA numbers by bank name and state. You can also ask the person directly or call their bank. ABA numbers are not secret — they are public information designed to route money correctly.