ABA Routing Number Validator
Validate US ABA routing numbers with the 3-7-1 checksum and Federal Reserve prefix. Free and private: runs in your browser.
Paste 9-digit routing numbers, one per line.
Numbers are checked locally in your browser and never sent anywhere. Use test data, not real customer details.
Use cases
- Validate test data for payment and banking flows.
- Catch typos in account and card details before calling a provider API.
- Explain money-handling rules to your team with real examples.
Frequently asked questions
How is the ABA checksum calculated?
Multiply the digits by 3, 7, 1, 3, 7, 1, 3, 7, 1 and add them up. The total must be a multiple of 10.
Is the ABA Routing Number Validator free?
Yes. It is free with no sign-up, and it runs entirely in your browser, so your input is never uploaded or stored.
Can I use real customer data here?
Avoid it. Everything runs locally, but good practice (and PCI DSS) is to use test data outside production systems.
Related tools
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