Your ABA number is a nine-digit code that identifies your specific bank
An ABA number (also called a routing number) is a nine-digit code that tells the banking system which bank holds your checking account. Think of it as your bank's address in the financial system. When money moves between banks — whether you're setting up direct deposit, paying a bill by check, or sending money to someone at a different bank — that ABA number is how the system knows where to send it.
The ABA stands for American Bankers Association, the organization that originally created this numbering system in 1910. Every bank in the United States has its own ABA number. If you have accounts at two different banks, each one has a different ABA number, even if you're in the same city.
Your ABA number is not secret and not sensitive. You'll find it printed on the bottom left of your checks, and you can share it freely. It only tells someone which bank you use — it doesn't let them access your money or your account.
Key Takeaways
- Your ABA number is a nine-digit code printed on the bottom left of your checks that identifies which bank holds your account.
- Banks use your ABA number to route money to the correct institution when you receive direct deposits, wire transfers, or ACH payments.
- Your ABA number is public information and safe to share — it only identifies your bank, not your specific account.
- You can find your ABA number on your checks, your bank's website, or by calling your bank's customer service line.
- Your ABA number is different from your account number; together they tell the banking system exactly where your money is.
Where to find your ABA number
The easiest place to find your ABA number is on a check from your checking account. Look at the bottom left corner of the check. You'll see three groups of numbers. The first group — nine digits — is your ABA number. The second group is your account number, and the third is the check number.
If you don't have checks or prefer not to look at them, you can find your ABA number on your bank's website. Log into your online banking account and look for a section called "Account Information," "Routing Number," or "Bank Details." Most banks display it there. You can also call your bank's customer service number (usually on the back of your debit card) and ask them to read it to you over the phone.
Some banks have multiple ABA numbers if they operate different divisions or acquired other banks. If you're setting up direct deposit or a wire transfer and your first attempt doesn't work, ask your bank whether there's a different routing number for that specific type of transaction.
How banks use your ABA number
When your employer sends you a paycheck through direct deposit, they use your ABA number and account number together to route that money to your specific bank and your specific account. Without the ABA number, the system wouldn't know which of thousands of banks to send it to.
The same process happens when you set up automatic bill payments, receive a wire transfer, or use an ACH transfer (a slower, cheaper way to move money between banks). Each time, the sending bank looks at your ABA number, finds your bank in the system, and delivers the money there. Your account number then tells your bank which account within that bank should receive it.
The ABA number is also used when you deposit a check from someone else. The check-processing system reads the ABA number on the check to know which bank to pull the money from.
The difference between ABA number and account number
Your ABA number identifies your bank. Your account number identifies your specific account within that bank. You need both pieces of information for money to reach the right place.
Think of it this way: the ABA number is like the street address of a large apartment building, and your account number is like your apartment number inside that building. The ABA number gets the money to the right building (bank). The account number gets it to the right unit (your account).
When you give someone your banking information for direct deposit or a wire transfer, you'll usually provide both numbers. Some forms ask for "routing number" (another name for ABA number) and "account number" in separate boxes. Others ask for "bank routing number" and "checking account number."
Why your ABA number is safe to share
Your ABA number is printed on every check you write and is public information. You can safely give it to your employer, your landlord, or anyone else who needs to send you money. Knowing your ABA number alone does not let someone access your account, withdraw money, or see your balance.
To actually move money out of your account, someone would need your account number and your permission, or they would need additional security information like your PIN or online banking password. Your ABA number is just the first piece of a much larger puzzle.
That said, you should still be cautious about who you give your full banking information to. While the ABA number itself is safe to share, your account number is more sensitive. Only provide both together to sources you trust — your employer, your bank, established bill-payment services, or financial institutions.
What happens if you use the wrong ABA number
If you accidentally give someone the wrong ABA number, the money will go to the wrong bank. The sending bank will try to deliver it there, and when the receiving bank can't find a matching account number, the money will usually bounce back to the sender within a few business days.
This is why it's worth double-checking your ABA number before you set up direct deposit for the first time or send a large wire transfer. A mistake won't cost you money, but it will delay the payment by several days while the system corrects the error.
If you're not sure whether you have the right ABA number, call your bank and confirm it before proceeding. It takes two minutes and prevents frustration later.
ABA numbers for different types of accounts
Your checking account has an ABA number. Your savings account at the same bank uses the same ABA number — the code identifies the bank, not the type of account. However, if you have accounts at two different banks, each bank has its own ABA number.
Some banks also have different ABA numbers for different branches or for different services (like wire transfers versus ACH transfers). This is less common now, but it can happen. If you're having trouble with a direct deposit or transfer, ask your bank whether there's a different routing number you should be using for that specific transaction type.
Frequently Asked Questions
Can someone steal money from my account if they know my ABA number?
No. Your ABA number only identifies which bank you use. To move money from your account, someone would need your account number, your permission, or access to your online banking password. The ABA number alone is not enough to access or withdraw funds.
Is my ABA number the same as my routing number?
Yes. "ABA number" and "routing number" are two names for the same nine-digit code. Banks and financial institutions use both terms interchangeably. You'll see both on banking forms and websites.
What if my bank merged with another bank — does my ABA number change?
Sometimes. If your bank was acquired by or merged with another bank, your ABA number may stay the same or may change depending on how the banks consolidated their systems. Contact your bank to confirm your current ABA number if you're unsure after a merger.
Do I need a different ABA number for wire transfers versus ACH transfers?
Usually not — the same ABA number works for both. However, some larger banks maintain separate routing numbers for different transaction types. If a wire transfer or ACH transfer fails, ask your bank whether there's an alternate routing number for that specific service.
Where do I find my ABA number if I bank online and don't have physical checks?
Log into your online banking account and look for "Account Information" or "Routing Number" in the settings or account details section. You can also call your bank's customer service line and ask them to provide it. Most banks will read it to you when ready.