What is a routing number? ACH vs wire routing numbers explained

A routing number is the nine-digit code that tells the US payment system which bank holds an account. Here is how it works for a business.

Rashidatou K.Payments editor

Published: 8 October 2026
Reading time: 2 min read

Every US bank account has two numbers that matter for getting paid: the account number and the routing number. "What is a routing number" is searched constantly, mostly by people setting up direct deposit. For a business, it decides whether US clients can pay you like a local supplier.

What a routing number is

The routing number, formally the ABA routing transit number, is a nine-digit code that identifies a US financial institution. The American Bankers Association created the system in 1910 and still administers it. Payment networks use it to deliver ACH payments, direct deposits and domestic wires to the right bank.

The structure carries meaning. The first four digits relate to the Federal Reserve district and processing centre, the next four identify the institution, and the ninth is a check digit calculated from the other eight, so many typos fail validation before a payment goes anywhere.

ACH and wire routing numbers

Some banks use a single routing number for everything. Others publish separate ones:

Rail	Which routing number
ACH (direct deposit, supplier payments)	The ACH or "electronic" routing number
Domestic wire (Fedwire)	The wire routing number, if the bank lists one
Paper checks	The number printed on the check

Use the one that matches the way the client will pay. The Federal Reserve's E-Payments Routing Directory lets you check which institutions a number is valid for on ACH and Fedwire. The ACH vs wire guide explains the two rails.

Where to find yours

Your online banking or app, under account details
Your bank's website, often on a "routing number" page by state
The bottom left of a US check
Your provider's account details screen, if you hold USD details with a fintech

Routing number, account number, SWIFT code

Number	Identifies	Used for
Routing number	The bank	US domestic payments
Account number	Your account	Every payment to you
SWIFT code	The bank, internationally	International wires; see what is a SWIFT code

For companies outside the US

A company registered in Kenya or the UK has no US routing number unless it holds US account details. With them, a US client pays by ACH or domestic wire, the cheapest ways for them to pay, and nothing passes through SWIFT. The USD account details guide shows how to put them on an invoice.

On Rivet

Rivet's free Starter plan includes USD details in your company's name with a routing number and account number for ACH and wires. See Bank accounts.

Questions people ask

What is a routing number for a bank account?

It is the nine-digit number that identifies the bank holding the account. Together with the account number, it lets a payer send ACH payments, direct deposits and domestic wires to that account.

Is the routing number the same for ACH and wire transfers?

Sometimes. Many banks use one number for both. Others publish a separate routing number for incoming wires. Check your bank's wire instructions and give the right one for each rail.

Where do I find my routing number?

In your online banking or app under account details, on your bank's website, or at the bottom left of a US check. For business accounts held with a fintech, it is on the account details screen.

Is it safe to share my routing number?

Yes. It identifies your bank and is public. Your account number is more sensitive, so share both only with people who need to pay you, and never change them by email alone.

Sources

Written by

Rashidatou K.

Payments editor

Rashidatou writes Rivet's guides to how money moves between countries: the payment rails, what each one costs, and the account details a company needs to get paid in another currency. Every figure in Rashidatou's articles is traced to the scheme rulebook, the regulator or the provider's published price list, and those sources are listed at the end.