Quick answer: A routing number is a nine-digit code that identifies a specific bank or credit union in the United States. It tells the payment system which financial institution should send or receive funds in a transaction. Routing numbers are required for direct deposits, ACH transfers, bill payments, and wire transfers. Every U.S. bank has at least one — large banks often have several, varying by state or transaction type.
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What is a routing number?
A routing number — formally called an ABA routing transit number — is a nine-digit identifier assigned to U.S. financial institutions by the American Bankers Association. It functions like an address for your bank: when money moves through the payment system, the routing number tells the network exactly which institution should send or receive the funds.
Routing numbers were introduced in 1910 to sort and process paper checks. They are now used for virtually all electronic payment types in the U.S. — ACH transfers, direct deposits, wire transfers, and bill payments all rely on routing numbers to route funds to the correct bank before the account number routes them to the correct account within that bank.
What routing numbers are used for
| Transaction type | Uses routing number? | Notes |
|---|---|---|
| Direct deposit (payroll, benefits) | Yes | Provide to employer or agency with account number |
| ACH transfer to external bank | Yes | Use ACH routing number — not wire routing number |
| Online bill payment | Yes | Usually ACH routing number |
| Domestic wire transfer | Yes | Some banks use a separate wire routing number |
| International wire transfer | No — use SWIFT code instead | Routing numbers are U.S.-only |
| Debit card purchase | No | Card network handles routing separately |
| Zelle payment | No | Zelle uses phone number or email, not routing number |
ACH routing number vs wire routing number
This is the most common source of routing number confusion. Some banks use the same routing number for both ACH transactions and wire transfers. Others use a different number for each. Using the wrong routing number for the transaction type causes the transfer to fail or be returned.
- ACH routing number — used for direct deposits, external bank transfers, bill payments, and most everyday electronic transactions; this is the number printed on your checks
- Wire routing number — used specifically for domestic wire transfers; at Chase, for example, the wire routing number is 021000021 regardless of which state the account is in, while ACH routing numbers vary by state
When in doubt about which routing number to use, contact your bank and specify the transaction type. For a full explanation of the difference between ACH and wire transfers, see what an ACH transfer is and how it works.
Why large banks have multiple routing numbers
When large banks expand into new states — through acquisitions or organic growth — they often inherit or establish separate routing numbers for each state or region. This is why Chase has a different ACH routing number for Texas than it does for California, and why Bank of America has different routing numbers across its footprint.
Your routing number is determined by the state where your account was originally opened — not your current address. If you moved from Ohio to Florida after opening your account, your Ohio routing number still applies. The fastest way to confirm the exact routing number for your specific account is to check your bank’s app under Account Details rather than relying on a general state-based lookup.
Where to find your routing number
- Your bank’s mobile app — tap your account and look for Account Details or Account Information; your routing number is listed there and is specific to your account
- Your checks — the nine-digit number in the bottom-left corner of a personal check is your ACH routing number
- Your bank’s website — log in and navigate to account details, or check the bank’s routing number lookup page
- Your bank’s customer service — call the number on the back of your debit card and ask; they can confirm the correct routing number for your account type and transaction type
Always verify your routing number through an official bank source before providing it for direct deposit or a transfer. Using a routing number from an unofficial third-party source is one of the most common causes of direct deposit failures. For bank-specific routing numbers, see the routing numbers directory.
Routing number vs account number
These two numbers work together but serve different purposes. The routing number identifies the bank; the account number identifies your specific account within that bank. Both are required for direct deposit setup, ACH transfers, and wire transfers.
- Routing number — nine digits; identifies the bank; the same for all accounts at the same bank in the same state
- Account number — typically 10–12 digits; unique to your specific account; different for every customer
On a personal check, the routing number is the nine-digit number at the far left of the number line at the bottom; the account number is the longer number to the right of it. For the full explanation, see what an account number is and how it differs from a routing number.
Are routing numbers safe to share?
Yes — routing numbers are not sensitive on their own. They identify the bank, not your account, and are publicly available information printed on every check. Sharing your routing number alone with someone cannot give them access to your account.
Your account number is more sensitive — it identifies your specific account and, combined with the routing number, is sufficient for someone to initiate an ACH debit from your account. Share your account number only with trusted parties — your employer for direct deposit, your bank for account linking, or a verified bill payment service. Never share both your routing and account number in response to an unsolicited request.
Common routing number mistakes
- Using the wrong state’s routing number — your routing number is tied to where the account was opened, not where you live now
- Using the ACH routing number for a wire transfer — some banks have separate wire routing numbers; using the wrong one causes the wire to fail
- Using a routing number from an unofficial source — always verify through your bank’s official app or website
- Confusing routing number with account number — both are required; neither alone is sufficient for a transfer
- Using a U.S. routing number for an international transfer — routing numbers only work within the U.S. banking system; international transfers require a SWIFT code
If a direct deposit or transfer fails because of a routing number issue, see common online banking problems and how to fix them for the troubleshooting steps.
Find your bank’s routing number
- Chase routing numbers by state
- Bank of America routing numbers by state
- Wells Fargo routing number
- PNC routing number
- Navy Federal routing number
- All routing numbers — full directory
Frequently Asked Questions
What is a routing number used for?
Routing numbers are used to identify your bank when sending or receiving money electronically. They are required for direct deposit setup with your employer, ACH transfers between banks, online bill payments, and domestic wire transfers. They are not used for debit card purchases, Zelle payments, or international wire transfers — which use different identification systems.
How many digits is a routing number?
A U.S. routing number is always exactly nine digits. If the number you have is longer or shorter than nine digits, it is either an account number, a card number, or an incomplete routing number. The nine-digit routing number is printed at the bottom-left of personal checks.
Can two banks have the same routing number?
No. Routing numbers are unique identifiers assigned by the American Bankers Association — no two financial institutions share the same routing number. However, one bank can have multiple routing numbers (for different states or transaction types), and after bank mergers, legacy routing numbers from acquired banks sometimes remain active for existing accounts.
Why does my bank have different routing numbers for different states?
Large banks that expanded into multiple states through acquisitions or organic growth often established separate routing numbers for each state or region. Your routing number is determined by the state where your account was originally opened — not your current address. If you moved states after opening your account, your original routing number still applies. Check your bank’s app under Account Details to confirm the routing number assigned to your specific account.
Is it safe to give someone my routing number?
Your routing number alone is safe to share — it identifies the bank, not your account, and is public information printed on every check. Sharing your routing number without your account number does not give anyone access to your funds. Your account number is more sensitive — share both only with trusted parties such as your employer for direct deposit or verified bill payment services.
Where is the routing number on a check?
The routing number is the nine-digit number at the far left of the number line printed at the bottom of a personal check. It is followed by your account number, then the check number. The routing number is always surrounded by special transit symbols that look like colons or broken lines — this helps check-processing machines identify where the routing number begins and ends.