A checking account has two main numbers: your account number and your routing number
Your account number is typically 8 to 12 digits long and identifies your specific account at your bank. Your routing number is always 9 digits and identifies the bank itself. Together, these two numbers let money move to and from your account. You'll need both when setting up direct deposit, paying bills by check, or sending money to someone else's account.
Some banks print both numbers on the bottom left of your checks in a specific order: routing number, then account number, then check number. Not all banks arrange them this way, and some online banks don't issue checks at all. If you can't find these numbers on a check, your bank's website or mobile app will show them in your account settings.
A few banks also assign you a separate customer ID number, which is different from your account number. This number identifies you as a customer across all your accounts with that bank, but you won't need it for most transactions. Your account number is what matters for moving money.
Key Takeaways
- Your account number (8 to 12 digits) identifies your specific checking account, while your routing number (always 9 digits) identifies your bank.
- Both numbers appear on the bottom left of paper checks, though the order varies by bank.
- You need both numbers to set up direct deposit, arrange automatic bill payments, or transfer money between accounts.
- Online banks and some credit unions may not issue checks, but they will still provide both numbers through your account settings or customer service.
- A customer ID number, if your bank assigns one, is separate from your account number and only needed for customer service inquiries.
Where to find your routing and account numbers
The easiest place to look is the bottom left corner of a paper check. The routing number comes first (9 digits), followed by your account number (8 to 12 digits), then the check number on the far right. However, not every bank prints them in this order, so check your bank's documentation if you're unsure which is which.
If you don't have checks or can't read them clearly, log into your bank's website or mobile app. Most banks display both numbers in the account details or settings section. You can also call your bank's customer service line or visit a branch in person—they can tell you both numbers over the phone or print them for you.
Some banks also send this information in your account opening paperwork or welcome letter. If you've kept those documents, the numbers should be listed there.
Why banks use two separate numbers instead of one
The routing number identifies the specific bank branch or processing center where your account lives. This number tells the payment system where to send the money. The account number then tells that bank which account within that institution should receive it. Separating them this way lets the payment system route money to the right place first, then to the right account second.
This two-number system also makes it easier for banks to merge, move branches, or change their internal structure without disrupting how money flows to your account. If a bank closes a branch, it can reassign accounts to a different routing number without changing your account number, so your direct deposit and automatic payments keep working.
What happens if you give someone the wrong number
If you give someone your account number but the wrong routing number, the money will go to the wrong bank and likely bounce back after a few days. The sending bank will see that the routing number doesn't match any real institution and return the funds to the sender.
If you give the right routing number but a wrong account number, the money may go to someone else's account at your bank. This is rarer because most banks have safeguards to catch mismatched numbers, but it can happen. Always double-check both numbers before giving them out, especially for large transfers or recurring payments like direct deposit.
If money does go to the wrong place, contact your bank immediately. They can often trace the payment and work with the other bank to recover it, but the faster you report it, the better your chances.
International transfers and additional numbers you might need
If you're receiving money from outside the United States, you may need additional numbers beyond your routing and account numbers. Many international transfers require a SWIFT code (a code that identifies your bank globally) or an IBAN (International Bank Account Number), which is used in Europe and some other regions.
U.S. banks don't use IBANs, but they do have SWIFT codes. Your bank can provide this code if you ask. Some banks also issue a separate code for wire transfers. Check with your bank about what information to give someone sending you money from abroad, because the requirements vary by country and by bank.
Checking account numbers on statements and tax forms
Your account number also appears on your monthly bank statements, usually at the top or in the account summary section. Some banks print it in full; others mask most of the digits for security and show only the last four. This masked version is normal and secure—the bank knows which account the statement belongs to.
You won't need your routing number for tax purposes, but you may need your account number if you're setting up a payment plan with the IRS or receiving a tax refund by direct deposit. The IRS will ask for your account number and routing number together when you choose direct deposit on your tax return.
Frequently Asked Questions
Can I change my account number?
Most banks will not change your account number unless there's fraud or a serious security breach. If you're concerned about your account number being compromised, contact your bank directly. They can close the account and open a new one with a different number if necessary, though this will require updating direct deposit and automatic payments.
Is my account number the same as my debit card number?
No. Your debit card has its own 16-digit number, which is different from your account number. The card number is used for purchases and ATM withdrawals. Your account number is used for transfers, direct deposit, and bill payments. You can have multiple debit cards linked to the same account, each with a different card number.
Do I need to memorize my routing and account numbers?
You don't need to memorize them, but it's helpful to know where to find them quickly. Write them down and store them somewhere safe, or take a photo of a check. You'll need them occasionally for direct deposit forms, wire transfers, or setting up automatic payments, so having them readily available saves time.
What if my bank merged with another bank—do my numbers change?
Your account number usually stays the same after a merger, but your routing number may change. The bank will notify you of any changes and update your account information. If you have direct deposit or automatic payments set up, contact your employer or billers to confirm they have the new routing number if the bank tells you it has changed.
Can someone steal money from my account if they know my account number?
Knowing only your account number is not enough to steal money. A person would also need your routing number, and even then, most banks require additional verification before processing transfers. However, don't share your account number with people you don't trust. If you suspect fraud, contact your bank immediately.