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ABA Routing Number Validator

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Validate a US bank routing number via its weighted mod-10 checksum (ABA routing number specification) and identify its Federal Reserve district and routing number type

Type or paste a 9-digit US bank routing number and get an instant weighted mod-10 checksum result, the same first-line check banks and payment processors run before accepting a routing number for an ACH transfer or direct deposit. It also identifies the routing number's type and Federal Reserve district from its first two digits: 01-12 are the 12 original Federal Reserve districts, 21-32 are the same districts reused for thrift institutions, 61-72 for electronic transactions, and 80 is reserved for traveler's checks. Nothing is sent anywhere: validation runs entirely in your browser and no routing number is stored or transmitted.

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How to use ABA Routing Number Validator

  • 1.Type or paste a 9-digit routing number into the input, with or without spaces or hyphens.
  • 2.Check the checksum result: a pass means the number is structurally valid, not that it belongs to a real active bank.
  • 3.Read the detected routing number type and Federal Reserve district to confirm it matches what you expected.

Frequently asked questions

Does this store or send my routing number anywhere?
No. Validation runs entirely client-side in your browser. Nothing is transmitted to a server, and nothing is logged or stored.
Does a passing checksum mean the bank actually exists?
No. The checksum only confirms the number is structurally valid, the same first-line sanity check a bank runs before doing a real routing lookup. It doesn't confirm the bank is active or the number is currently assigned.
What do the routing number types mean?
The first two digits indicate how the number is used: 01-12 are the original Federal Reserve district codes used for most paper and electronic transactions, 21-32 are the same districts reused for thrift institutions, 61-72 for electronic-only transactions, and 80 is reserved for traveler's checks. A prefix outside those ranges is reported as unknown.
Does this work for international bank codes like IBAN or SWIFT?
No, this checks the US-specific ABA/RTN format only. Use the separate IBAN Validator / Formatter tool for international account numbers.

Use via API, SDK, or MCP

cURL# Free: 1,000 req/day · Pro: 10,000 req/day
curl -X POST https://api.utilix.tech/v1/tools/aba-routing-number-validator \
  -H "Authorization: Bearer utx_live_..." \
  -H "Content-Type: application/json" \
  -d '{"routingNumber":"021000021"}'

Get an API key from your dashboard · Full API docs →

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