IBAN generator for testing

Every IBAN above is built from the official format of its country and carries correct check digits, so it goes through the same validation as a real one. The bank code and the account number are random, which means none of them belongs to a real account. Pick another country or amount and you get a new list straight away.

What an IBAN is made of

An IBAN (International Bank Account Number) always has three parts. Take the German example IBAN DE89 3704 0044 0532 0130 00:

• Country code, two letters: DE.
• Check digits, two numbers calculated from everything else: 89.
• BBAN, the national account number. In Germany it is an 8-digit bank code (37040044) followed by a 10-digit account number (0532013000).

The length and layout of the BBAN are fixed per country: 22 characters in Germany and the United Kingdom, 24 in Spain, 27 in France and Italy, 18 in the Netherlands. Some countries use letters, like the four-letter bank code of a British IBAN (GB29 NWBK …). The generator follows each layout, so a UK IBAN gets letters where a UK validator expects them.

How the check digits work

The two check digits catch almost any typo. They come from the mod 97 algorithm of ISO 13616:

1. Move the country code to the endWrite the BBAN, then the country code and 00: 370400440532013000DE00.
2. Turn letters into numbersA becomes 10, B becomes 11 and so on up to Z = 35. DE becomes 1314.
3. Divide by 97Take the remainder of that long number divided by 97. Here it is 9.
4. Subtract from 9898 − 9 = 89, padded to two digits. Those are the check digits.

Validating is the same in reverse: move the first four characters to the end, convert the letters and check that the remainder of dividing by 97 is exactly 1.

function isValidIban(iban) {
  const s = iban.replace(/\s+/g, '').toUpperCase();
  const moved = s.slice(4) + s.slice(0, 4);
  const digits = moved.replace(/[A-Z]/g, c => c.charCodeAt(0) - 55);
  let rest = 0;
  for (const d of digits) rest = (rest * 10 + +d) % 97;
  return rest === 1;  // also check the length for the country
}

National check digits

Several countries add their own check digits inside the BBAN, and strict validators test them as well. The generator calculates them for:

• Spain: the two dígitos de control after the bank and branch codes.
• France and Monaco: the two-digit clé RIB at the end.
• Italy and San Marino: the CIN letter at the start of the BBAN.
• Portugal: the two NIB check digits at the end.
• Belgium: the last two digits, the remainder of the first ten divided by 97.
• Norway: the final mod 11 digit.

IBAN formats by country

The length and one generated example for each country the tool supports. None of the examples is a real account.

Fill IBAN fields automatically

Copying an IBAN is fine once. When you test a sign-up or checkout form many times a day, the rest of the form needs data too: names, email, phone, address, tax ID. Form Filler is a Chrome extension that fills the whole form in one click, with data for the country you choose.

The free version fills IBAN fields with the right country prefix and length. Pro makes them checksum-valid and also generates valid national IDs such as the Spanish NIF, the German Steuer-ID or the Italian Codice Fiscale. The guide on how to autofill forms in Chrome covers the setup, and how to generate test data for web forms compares it with Faker and other options.