What is a routing number?

A routing number is a nine-digit code that identifies a US bank or credit union. Paired with your account number, it tells the payment network where to send money. You will see it on checks, in your online banking, and on invoices that accept ACH transfers.

How it works

When a client pays you by ACH or domestic wire, their bank needs two facts: which institution holds your money, and which account to credit. The routing number answers the first question. The account number answers the second.

The nine digits are not random. The first four digits are the Federal Reserve routing symbol, the next four identify the institution, and the last digit is a check digit that catches typing errors. Large banks can have several routing numbers, and the number for ACH can differ from the number for wires. Always copy the one your bank lists for the payment type you want.

On an invoice, the routing number belongs in the payment instructions next to the account name and account number. Many freelancers now skip it and send a payment link, which keeps bank details off the page entirely. For a deeper look at the network behind these transfers, see ACH.

Example

Here is how the check digit works. Take this fake sample number: 123456780. It is not a real bank. Multiply the digits by the repeating weights 3, 7, 1 and add the results.

On a real invoice, the payment block might read: Account name: Acme Studio LLC, Routing: 123456780, Account: 000123456789. Use the invoice generator to add payment instructions to a PDF today. PayToMe’s built-in payments are in development, so for now the generator is the live option.

Related terms

• ACH: the US network that uses routing numbers to move bank-to-bank payments.
• IBAN: the international account identifier used across Europe.
• SWIFT code: the bank identifier for cross-border wires.
• Remittance advice: the notice that tells you which invoice a payment covers.