Routing number vs account number
They appear next to each other on every check, and they're both required for any electronic transfer. But they identify completely different things.
The short version
The routing number identifies the bank. The account number identifies you within that bank. Together, they form the unique address that any payment system needs to deliver money into the right account.
Why two numbers are needed
Think of the US payments system as a national postal service for money. The routing number is the equivalent of a ZIP code — it tells the system which bank, in which Federal Reserve district, should receive the payment. The account number is the equivalent of a street address — it tells that bank which specific customer to credit. Without the routing number, the payment can't find the bank; without the account number, the bank doesn't know who to credit.
Key differences
| Routing number | Account number |
|---|---|
| Identifies the bank | Identifies the customer |
| Always exactly nine digits | Usually 8–12 digits, varies by bank |
| Public information; printed on every check | Sensitive; treat like a credit card number |
| Issued by the ABA / Federal Reserve | Assigned by your bank when you open the account |
| Same for everyone at the same bank/region | Unique to you |
Where to find each
On a paper check, the routing number is the leftmost nine-digit group along the bottom edge, bracketed by transit symbols (⑈). The account number is the middle group, ending just before the check number on the right. In your online banking dashboard, both appear together — usually labeled "Routing & Transit Number" and "Account Number" — under account details or "set up direct deposit."
Privacy: how careful should you be?
The routing number alone is not sensitive. It's printed on every check you write, listed in public directories like RoutingRadar, and shared freely whenever you give someone your bank's name. Knowing your bank's routing number does not allow anyone to access your money.
The account number is far more sensitive. Combined with the routing number, the account number can be used to originate ACH debits — meaning a fraudster could attempt to pull money from your account. Consumer banking regulations (Regulation E) require your bank to refund unauthorized ACH debits if you report them within 60 days, but the recovery process is slow and stressful. Treat your account number with the same care you give your debit-card number, and avoid posting either online.