IBAN Validator API

GET

Check any IBAN and see why it fails, down to the digit.

IBAN Validator checks an IBAN's mod-97 checksum, its length and format for the country, and national check digits where the country defines them. It returns whether the IBAN is valid, the country and the reasons it fails. Paid plans add the bank code, branch code and account number, the correct check digits and the SEPA flag.

Try it — live request, no key required

Request

GETapi.apiverve.com/v1/ibanvalidator?iban=GB29NWBK60161331926819

Query parameters

ibanstring

Verification

Format

No key required to try it. Get a key to use it in your app.

Example

{
  "status": "ok",
  "error": null,
  "data": {
    "iban": "GB29NWBK60161331926819",
    "isValid": true,
    "formatted": "GB29 NWBK 6016 1331 9268 19",
    "countryCode": "GB",
    "countryName": "United Kingdom",
    "checkDigits": "29",
    "expectedLength": 22,
    "length": 22,
    "errors": [],
    "bban": "NWBK60161331926819",
    "bankCode": "NWBK",
    "branchCode": "601613",
    "accountNumber": "31926819",
    "nationalCheckDigits": null,
    "expectedCheckDigits": "29",
    "isSEPA": true,
    "isQRIBAN": false
  }
}

About the IBAN Validator API

Validation follows the SWIFT IBAN registry and covers 124 countries and territories, including all 97 registry countries. Spaces, dashes and lower case are accepted. An invalid IBAN is not an error: it returns isValid false with the reasons, and the check digits it should have had.

What people use it for

Payment Forms: Validate an IBAN as it is typed at checkout or payout setup, and show the reason it fails before a transfer bounces.
Supplier Onboarding: Check the bank details suppliers submit and pull out the bank and branch codes for your records.
SEPA Direct Debit: Confirm a customer's IBAN is valid and in a SEPA country before creating a mandate.
Data Cleaning: Normalise stored IBANs to electronic and print formats, and flag the ones with bad checksums.

Ways to call it

One endpoint, many ways in — REST with JSON, XML, YAML and CSV, plus GraphQL and an MCP interface for AI agents.

JSON: Default REST response
XML: Markup format
YAML: Human-readable
CSV: Tabular export
GraphQL: Query language
MCP: For AI agents

View all integrations →

Other ways to use IBAN Validator

Same data, same APIVerve account, same credit balance — one key works on all of them.

Give it to an AI agentConnect over MCP and your agent calls it as a native tool — Claude, Cursor, ChatGPT.on VerveKit Google Sheets or ExcelA =VERVE() formula fills a column — no script, no export, recalculates in place.on VerveSheets Ground an agent on itA cited, machine-checkable fact your model can't produce on its own.on VerveContext

Questions.

Common questions about the IBAN Validator API.

Read the docs →

How many IBAN checks does the Starter plan cover?

Starter covers 100,000 IBAN checks each month. At 2 credits per request, that works out to $0.30 per 1,000 checks, or about $0.0003 per check. The Free plan includes 100 checks per month for testing.

What does the Free plan return?

The Free plan returns isValid, the IBAN in electronic and print formats, the country code and name, the check digits, the expected and actual length, and the list of errors. Paid plans add the BBAN, bank code, branch code, account number, national check digits, the correct IBAN check digits, and the SEPA and QR-IBAN flags.

What is checked?

The mod-97 checksum, the length and BBAN format for the country from the SWIFT IBAN registry, and the national check digits for countries that define them, such as Spain, Belgium and Poland. It does not confirm that the account exists or is open.

What happens with an invalid IBAN?

It returns a normal response with isValid false and an errors list, such as a wrong checksum or the wrong length for the country. On paid plans, expectedCheckDigits gives the check digits the IBAN would need, which catches simple typos.

For which countries is the account number returned?

The bank code comes from the SWIFT registry for most countries. The account number is returned for 36 countries whose domestic format fixes its position, including Germany, France, Italy, Spain, the UK, the Netherlands and Poland, and is null elsewhere.

Request parameters — GET /v1/ibanvalidator

Sent in the query string. Premium parameters are accepted on every plan but only take effect on plans that include them. Anything not listed here is dropped rather than passed through.

Required

Parameter	Type	Example	Description
`iban`Required	string	`GB29NWBK60161331926819`	The IBAN to validate. Spaces, dashes and lower case are accepted length 0-64

Example request

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curl "https://api.apiverve.com/v1/ibanvalidator?iban=GB29NWBK60161331926819" \
  -H "x-api-key: YOUR_API_KEY"

Authentication

Send your key in the x-api-key header. That is the only auth step — no token exchange, and no per-endpoint scope to configure.

Header	When	Value
`x-api-key`Required	Every request	Your API key. Header names are case-insensitive, so `X-API-Key` is the same header.
`Authorization`Alternate	Instead of the above	`Bearer <key>` — for clients that only expose bearer auth. Resolves to the same account and the same billing.

401 is the only auth verdict

A 401 means the key is missing, invalid or expired. A 403 means the key is valid but not permitted here — blocked by a key restriction or an IP allow-list. Running out of credits is a 429.

Response — GET /v1/ibanvalidator

Every APIVerve endpoint returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape.

Sample response

{
  "status": "ok",
  "error": null,
  "data": {
    "iban": "GB29NWBK60161331926819",
    "isValid": true,
    "formatted": "GB29 NWBK 6016 1331 9268 19",
    "countryCode": "GB",
    "countryName": "United Kingdom",
    "checkDigits": "29",
    "expectedLength": 22,
    "length": 22,
    "errors": [],
    "bban": "NWBK60161331926819",
    "bankCode": "NWBK",
    "branchCode": "601613",
    "accountNumber": "31926819",
    "nationalCheckDigits": null,
    "expectedCheckDigits": "29",
    "isSEPA": true,
    "isQRIBAN": false
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Field	Type	Example	Description
`iban`	string	`"GB29NWBK60161331926819"`	The IBAN in electronic format (no spaces, upper case)
`isValid`	boolean	`true`	True when the checksum, length, format and any national check digits are all correct
`formatted`	string	`"GB29 NWBK 6016 1331 9268 19"`	The IBAN in print format, in groups of four, or null when invalid
`countryCode`	string	`"GB"`	ISO 3166-1 alpha-2 country code
`countryName`	string	`"United Kingdom"`	Country name
`checkDigits`	string	`"29"`	The two check digits as given
`expectedLength`	number	`22`	IBAN length for the country, or null when the country does not use IBANs
`length`	number	`22`	Length of the IBAN given
`errors`	array	`[]`	Why the IBAN is invalid; empty when valid
`bban`Premium	string	`"NWBK60161331926819"`	The Basic Bank Account Number (everything after the check digits)
`bankCode`Premium	string	`"NWBK"`	Bank identifier, where the country defines one
`branchCode`Premium	string	`"601613"`	Branch identifier or sort code, where the country defines one
`accountNumber`Premium	string	`"31926819"`	Domestic account number, for countries whose format fixes its position
`nationalCheckDigits`Premium	object	`null`	National check digits inside the BBAN, where the country defines them
`expectedCheckDigits`Premium	string	`"29"`	The IBAN check digits the BBAN requires, which differ from checkDigits when the checksum is wrong
`isSEPA`Premium	boolean	`true`	True when the country is in the SEPA scheme
`isQRIBAN`Premium	boolean	`false`	True for a Swiss or Liechtenstein QR-IBAN

Response headers

Every response carries your balance, so your own code always knows where it stands without polling anything. All four are exposed to browsers through CORS.

Header	What it carries
`x-api-remaining-credits`	Credits left in the current cycle
`x-api-credits-used`	Credits spent in the current cycle
`x-api-max-credits`	The allowance for the cycle
`x-api-version`	Version of the endpoint that answered

Errors

Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change.

Status	Meaning	What to do
`400`	Input was rejected	Read `error`; it names the parameter that has to change.
`401`	Key missing or invalid	Check the header name and the key value.
`403`	Key valid, but not permitted here	A key restriction or an IP allow-list — never a bad key.
`429`	Rate limited, or out of credits	Read `error` to tell them apart, then back off or top up.

What a call costs — 2 credits per call

Credits are shared across every APIVerve API — one balance, one key, one bill. Failed requests never count against it, so a rejected input costs nothing.

Plan	Per month	Credits	IBAN Validator calls	Per 1,000 calls
Free	Free	200	100	Free
Starter	$29.99	200,000	100,000	$0.30
Pro	$99.99	1,000,000	500,000	$0.20
Mega	$299.99	4,000,000	2,000,000	$0.15

Calls are what the credits buy at this API's rate — spend them here, on any of the other APIs, or across both. Nothing is reserved per endpoint.

Compare all pricing tiers →

Call it from cURL — GET /v1/ibanvalidator

No SDK to install — this is a plain HTTPS call to /v1/ibanvalidator with your key in the x-api-key header. Swap in a real key and it runs as-is.

cURL

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curl "https://api.apiverve.com/v1/ibanvalidator" \
  -H "x-api-key: YOUR_API_KEY"

Resources

ReferenceIBAN Validator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Call it from Node.js — GET /v1/ibanvalidator

No SDK to install — this is a plain HTTPS call to /v1/ibanvalidator with your key in the x-api-key header. Swap in a real key and it runs as-is.

Node.js

const res = await fetch("https://api.apiverve.com/v1/ibanvalidator", {
  headers: { "x-api-key": "YOUR_API_KEY" },
});
const { data } = await res.json();
console.log(data);

Resources

ReferenceIBAN Validator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Call it from Python — GET /v1/ibanvalidator

No SDK to install — this is a plain HTTPS call to /v1/ibanvalidator with your key in the x-api-key header. Swap in a real key and it runs as-is.

Python

import requests

res = requests.get(
    "https://api.apiverve.com/v1/ibanvalidator",
    headers={"x-api-key": "YOUR_API_KEY"},
)
print(res.json()["data"])

Resources

ReferenceIBAN Validator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Call it from C# / .NET — GET /v1/ibanvalidator

No SDK to install — this is a plain HTTPS call to /v1/ibanvalidator with your key in the x-api-key header. Swap in a real key and it runs as-is.

C# / .NET

using var client = new HttpClient();
client.DefaultRequestHeaders.Add("x-api-key", "YOUR_API_KEY");

var json = await client.GetStringAsync("https://api.apiverve.com/v1/ibanvalidator");
Console.WriteLine(json);

Resources

ReferenceIBAN Validator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Call it from Go — GET /v1/ibanvalidator

No SDK to install — this is a plain HTTPS call to /v1/ibanvalidator with your key in the x-api-key header. Swap in a real key and it runs as-is.

req, _ := http.NewRequest("GET", "https://api.apiverve.com/v1/ibanvalidator", nil)
req.Header.Set("x-api-key", "YOUR_API_KEY")

res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))

Resources

ReferenceIBAN Validator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Call it from PHP — GET /v1/ibanvalidator

No SDK to install — this is a plain HTTPS call to /v1/ibanvalidator with your key in the x-api-key header. Swap in a real key and it runs as-is.

PHP

$ch = curl_init("https://api.apiverve.com/v1/ibanvalidator");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-api-key: YOUR_API_KEY"]);

$response = curl_exec($ch);
echo $response;

Resources

ReferenceIBAN Validator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Call it from Ruby — GET /v1/ibanvalidator

No SDK to install — this is a plain HTTPS call to /v1/ibanvalidator with your key in the x-api-key header. Swap in a real key and it runs as-is.

Ruby

require "net/http"

uri = URI("https://api.apiverve.com/v1/ibanvalidator")
req = Net::HTTP::Get.new(uri)
req["x-api-key"] = "YOUR_API_KEY"

res = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) { |h| h.request(req) }
puts res.body

Resources

ReferenceIBAN Validator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

IBAN Validator API

Try it — live request, no key required

About the IBAN Validator API

What people use it for

Ways to call it

Other ways to use IBAN Validator

Questions.

Request parameters — GET /v1/ibanvalidator

Required

Authentication

Response — GET /v1/ibanvalidator

Response fields

Response headers

Errors

What a call costs — 2 credits per call

Call it from cURL — GET /v1/ibanvalidator

Resources

Call it from Node.js — GET /v1/ibanvalidator

Resources

Call it from Python — GET /v1/ibanvalidator

Resources

Call it from C# / .NET — GET /v1/ibanvalidator

Resources

Call it from Go — GET /v1/ibanvalidator

Resources

Call it from PHP — GET /v1/ibanvalidator

Resources

Call it from Ruby — GET /v1/ibanvalidator

Resources

Zero-code embed — one snippet, no backend

Changelog — IBAN Validator API

Data Validation

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