ComputeFirst

Validate an IBAN from an AI agent

You need to check an IBAN that a person typed or a document contains: its country, its length and its check digits.

**Use iban-validate@1.0.0.** It is free and needs no key or sign-up. Validate an IBAN's country, registry length, BBAN structure and MOD 97-10 check digits, and parse its bank/branch code.

Why call a tool for this

The MOD 97-10 check works on the whole number, and one wrong digit changes the outcome. The tool also returns the country, the check digits and the reason an IBAN failed.

Call it over HTTP

curl -X POST https://computefirst.net/v1/tools/iban-validate/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"iban":"GB29NWBK60161331926819"}'

Response:

{
  "result": {
    "electronic": "GB29NWBK60161331926819",
    "print": "GB29 NWBK 6016 1331 9268 19",
    "data_version": "swift-iban-registry-103-2026-09.subset-80",
    "valid": true,
    "reason": null,
    "country": "GB",
    "check_digits": "29",
    "bban": "NWBK60161331926819",
    "bank_code": "NWBK",
    "branch_code": "601613"
  }
}

Call it over MCP

Connect https://computefirst.net/mcp (setup), then call execute with:

{
  "id": "iban-validate",
  "version": "1.0.0",
  "input": {
    "iban": "GB29NWBK60161331926819"
  }
}

Check the result

A valid IBAN has a correct structure and correct check digits. That does not show that the account exists. The response names the registry snapshot it used in data_version. Check reason: unknown_country means the country is outside that snapshot, not that the IBAN is wrong.

Full contract, limits and unsupported cases: Iban validate.