# 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

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

Response:

```json
{
  "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](/docs#connect)), then call `execute` with:

```json
{
  "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](/tools/iban-validate).

## Related tools

- [Iban compute from bban](/tools/iban-compute-from-bban)
- [Checkdigit validate](/tools/checkdigit-validate)