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Software Routing number checker
Validate a US ABA routing number before you send an ACH transfer or wire, or search a bank name to see the numbers it publishes.
Private by design
Checked in your browser, never sent or stored.
Checksum and prefix
The ABA check digit and Federal Reserve routing symbol.
Search by bank name
Numbers large US banks publish.
How the checksum works
Multiply the nine digits by 3, 7, 1, 3, 7, 1, 3, 7 and 1 in turn and add the results. For a valid routing number the total is a multiple of 10.
Where the bank numbers come from
The bank search lists numbers as each bank publishes them on its own site, checked on September 30, 2026. It is a curated list of large banks, not a full directory, and banks change routing numbers after mergers. A routing number identifies the bank, not your account: confirm payment instructions with the receiving bank.
For AI agents
Free for AI agents too, as validateRoutingNumber, with no key or install: browser agents get it through WebMCP, and any agent can call the JSON API.
An ABA routing number is a nine-digit number used to identify a US financial institution for payments. The first four digits form the Federal Reserve routing symbol, the next four identify the institution, and the final digit is a checksum.
Many banks use different numbers for wires and ACH, and larger banks use different ACH numbers by the state where the account was opened. Always use the number the recipient's bank gives for the payment type you are sending.
Not necessarily. Passing the format and checksum checks does not confirm that a routing number is currently assigned or can receive your payment, so confirm it with the recipient or their bank.
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from one account.
USD and EUR accounts, global payments, and corporate cards in one global business account.
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