ABA Routing Number Validator

Check a US bank routing number's checksum and decode where it comes from.

9 digits. Spaces and hyphens are OK — they are ignored.

Enter a routing number to validate it.

What is an ABA routing number?

An ABA routing number — also called a routing transit number (RTN) — is the nine-digit code that identifies a US bank or credit union in ACH transfers, Fedwire payments and direct deposits. It is assigned by the American Bankers Association and tells the payment network exactly which institution to route the money to.

You can find your routing number on the bottom-left of a paper check (the first group of nine digits), in your bank's mobile app, or on its website. Large banks often use several routing numbers depending on the state where you opened the account and the type of payment.

How to validate a routing number

  • Type or paste the 9-digit routing number into the field above.
  • The tool instantly runs the 3-7-1 weighted checksum (mod 10) that every valid routing number must satisfy.
  • The first two digits are decoded to show the Federal Reserve district and the institution type behind the number.
  • A green result means the checksum is valid and the prefix is recognized; a red result means the number cannot exist.
  • Use the verified number in ACH, wire and direct-deposit forms as usual.

Tips

  • Routing numbers are public information — checking one is completely safe.
  • Large banks can have dozens of routing numbers, split by state or account type, so make sure the number belongs to the state of your account.
  • Some banks use different routing numbers for wire transfers than for ACH and direct deposit — check which one the form asks for.

Frequently Asked Questions

What is an ABA routing number?+
It is the nine-digit code that identifies a US bank or credit union when money moves through ACH, Fedwire or a direct deposit. It was introduced by the American Bankers Association in 1910 and is printed on every US check.
How does the 3-7-1 checksum work?+
The first, fourth and seventh digits are multiplied by 3, the second, fifth and eighth by 7, and the third and sixth by 1. Adding these products and taking the result modulo 10 must give 0 — the last digit of the routing number makes that true. This catches nearly every typo.
Where do I find my routing number?+
Look at the bottom-left corner of a paper check — the nine-digit group between the symbols is the routing number. You can also find it in your banking app, on your bank's website, or on your account statements.
Can two banks share the same routing number?+
No. Every routing number points to exactly one institution. However, one bank can hold many routing numbers — large banks assign different numbers per state, and often separate ones for wires, ACH and paper checks.

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ABA Routing Number Validator — free online aba routing number, routing number check, routing number validator, bank routing number lookup, aba number, fedwire routing number. No signup required. Works in your browser.