A routing number is always nine digits
Every bank routing number in the United States contains exactly nine digits. No more, no fewer. This nine-digit format is a standard set by the American Bankers Association and used by all banks, credit unions, and financial institutions that participate in the Federal Reserve system.
The nine digits are not random. They follow a specific structure that identifies the bank, the region where it operates, and the Federal Reserve district it belongs to. When you write a check or set up a wire transfer, those nine digits tell the banking system exactly where to send or pull money.
If you see a number that claims to be a routing number but has fewer or more than nine digits, it is not a routing number. It might be an account number, a transit number from another country, or something else entirely.
Key Takeaways
- All U.S. bank routing numbers contain exactly nine digits with no letters or special characters.
- The first four digits identify the Federal Reserve district and the bank's home state.
- The middle four digits identify the specific bank or branch within that district.
- The last digit is a check digit that verifies the routing number is valid.
- If a number has more or fewer than nine digits, it is not a routing number.
Where to find your routing number
Your routing number appears in three places: the bottom left corner of your checks, your bank's website (usually under account information or help sections), and by calling your bank directly. If you use online banking, you can log in and look for account details or settings.
Some banks display the routing number on statements or in the mobile app. Credit unions use routing numbers too, and the same nine-digit rule applies. If you cannot find it quickly, call the customer service number on the back of your debit card or on your bank's website.
What each part of the routing number means
The nine digits break down into three groups of four, four, and one. The first four digits identify which Federal Reserve district the bank belongs to and which state it is in. For example, routing numbers starting with 0210 belong to banks in the Boston Federal Reserve district.
The middle four digits identify the specific bank or financial institution. Two banks in the same Federal Reserve district will have different middle digits. The last single digit is a check digit—a mathematical verification that the first eight digits are correct. This prevents typos from sending money to the wrong place.
You do not need to memorize or understand this breakdown to use your routing number. But knowing the structure helps you spot errors. If someone gives you a routing number and you are unsure whether it is correct, you can verify it by calling the bank directly or checking their official website.
Routing numbers versus account numbers
A routing number and an account number are different. The routing number identifies the bank; the account number identifies your specific account at that bank. Your account number is usually 10 to 12 digits long and appears on your checks to the right of the routing number.
For a wire transfer or direct deposit, you need both. The routing number tells the system which bank to use. The account number tells the bank which account within that bank to credit or debit. Mixing them up will send money to the wrong place or cause the transaction to fail.
International routing numbers are different
If you are sending money to or from another country, that country's banks use different routing systems. Canada uses a nine-digit transit number that looks similar to a U.S. routing number. The United Kingdom uses a six-digit sort code. Mexico uses a three-digit bank code plus a three-digit branch code.
These international systems do not follow the American Bankers Association standard. If you are moving money across borders, ask your bank what routing or transit information the receiving bank needs. Do not assume a nine-digit number from another country is a routing number in the U.S. sense.
What happens if you use the wrong routing number
If you provide an incorrect routing number, the transaction will either fail or go to the wrong bank. For checks, the money may be sent to a different institution, and you will have to contact your bank to trace it. For direct deposits and wire transfers, the receiving bank usually rejects the transaction and sends it back within one to three business days.
If money does go to the wrong bank by mistake, contact your bank when ready. Provide them with the incorrect routing number, the amount, and the date of the transaction. Your bank can file a trace and work with the other institution to recover the funds. The sooner you report it, the faster the process moves.
Frequently Asked Questions
Can a routing number have letters in it?
No. A routing number contains only nine digits (0 through 9). If you see letters mixed in, it is not a routing number. It might be an account number, a reference code, or something else.
Do all banks in the same state have the same routing number?
No. Each bank or credit union has its own routing number, even if multiple banks operate in the same state. The first four digits identify the Federal Reserve district and state, but the middle four digits are unique to each institution.
Is my routing number the same for checking and savings accounts?
Yes. Your routing number is the same for all accounts you hold at that bank. The account number changes from account to account, but the routing number stays the same.
What if my bank merged with another bank?
Your routing number may change after a merger. Contact your bank to confirm your current routing number. If you have automatic payments or direct deposits set up, you may need to update them with the new routing number.
Can I use someone else's routing number to send them money?
Yes. The routing number is public information. You need the routing number of the bank where the other person holds their account, plus their account number. The routing number alone does not give anyone access to the account.