An ABA number is a nine-digit code that identifies the specific bank or credit union where you hold your account
The ABA number (also called a routing number or routing transit number) tells the banking system which financial institution to send money to when you receive a wire transfer, direct deposit, or automatic payment. It is not the same as your account number. Your account number identifies you within that bank; the ABA number identifies the bank itself.
Every bank and credit union in the United States has its own ABA number. When you set up direct deposit for a paycheck or arrange for a bill to be paid automatically from your account, you provide both your ABA number and your account number so the money reaches the right place.
Key Takeaways
- An ABA number is a nine-digit code assigned to your bank or credit union by the American Bankers Association, and it appears on the bottom left of every check you receive.
- You need your ABA number whenever you set up direct deposit, wire transfers, automatic bill payments, or any transfer that moves money between banks.
- Your ABA number is public information and safe to share — it identifies only the bank, not your account or personal details.
- Different branches of the same bank usually share one ABA number, though some large banks assign different numbers to different regions.
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 of the check — you will see nine digits printed there. That is your ABA number. The middle set of numbers (usually eight digits) is your account number.
If you do not have a check handy, you can find your ABA number by logging into your bank's website or mobile app and looking in the account details or settings section. Most banks label it as "routing number" or "ABA number." You can also call your bank's customer service line and ask — they will give it to you over the phone.
If you bank at a credit union, the same rules apply. Your ABA number will be on your checks, in your online account, or available by phone.
Why banks use ABA numbers instead of just account numbers
The banking system processes millions of transactions every day between thousands of different banks. Without a standardized way to identify each bank, money would get lost or sent to the wrong place. The ABA number solves this by giving every bank a unique code that the Federal Reserve and other banks can recognize instantly.
When you set up direct deposit at a new job, for example, your employer's payroll system uses your ABA number to route your paycheck to your specific bank, and then your account number directs it to your specific account within that bank. The two numbers work together.
ABA numbers and wire transfers
Wire transfers — moving money quickly between banks — require both your ABA number and your account number. When you send a wire, you provide the recipient's ABA number so the sending bank knows which bank to contact. The receiving bank then uses the account number to deposit the money in the right account.
International wire transfers use a different code called a SWIFT code instead of an ABA number, because SWIFT codes identify banks outside the United States. If you are sending money to another country, ask the recipient for their SWIFT code rather than their ABA number.
Is it safe to share your ABA number?
Yes. Your ABA number is public information and sharing it carries no risk. It identifies only your bank, not your account or your identity. Think of it like your bank's address — anyone can know where your bank is located, but that does not mean they can access your money.
You should never share your full account number with people you do not trust, but your ABA number alone cannot be used to withdraw money or access your account. You will need to provide your ABA number to your employer, your landlord (if rent is auto-drafted), insurance companies, and any service that sends you money or takes automatic payments from your account.
What happens if you use the wrong ABA number
If you provide an incorrect ABA number when setting up direct deposit or a transfer, the money will go to the wrong bank. The receiving bank will usually reject the deposit and send it back to the sender, which can take several business days. During that time, you will not have access to the money.
If the wrong bank accepts the deposit by mistake, it may take weeks to recover the funds. This is why it is important to double-check your ABA number before submitting it, especially for large transfers or important payments like payroll.
ABA numbers and different branches
Most banks use the same ABA number for all their branches nationwide. If you have an account at Bank of America in New York and transfer money to a Bank of America account in California, both use the same ABA number. The account number is what distinguishes your account from every other account at that bank.
Some very large banks or regional banks may assign different ABA numbers to different regions or divisions, but this is less common. If you are unsure whether your branch has its own ABA number, check a check from your account or contact your bank directly.
Frequently Asked Questions
Is my ABA number the same as my routing number?
Yes, they are the same thing. "ABA number" and "routing number" are two names for the same nine-digit code. Some banks call it a routing transit number (RTN). You will see all three terms used interchangeably.
Can someone steal money from my account if they have my ABA number?
No. Your ABA number alone does not give anyone access to your account. They would also need your full account number and other information. Treat your account number as private, but your ABA number is safe to share.
What if my bank merged with another bank — does my ABA number change?
Usually not immediately. After a merger, banks often keep the original ABA numbers for existing accounts to avoid disrupting direct deposits and automatic payments. Your bank will notify you if your ABA number changes, and you would need to update it with your employer or any services using it.
Do credit unions have ABA numbers?
Yes. Credit unions are part of the same banking system and have their own ABA numbers. You will find your credit union's ABA number on your checks, in your online account, or by calling the credit union.
Why do I need an ABA number if I am receiving money from outside the US?
International transfers use SWIFT codes instead of ABA numbers. If someone outside the US is sending you money, provide them with your bank's SWIFT code and your account number, not your ABA number.