Question 1

What is an IBAN and what does validating it mean?

Accepted Answer

IBAN stands for International Bank Account Number — a standardised format used across 80+ countries to identify bank accounts for international transfers. Validating an IBAN means checking two things: (1) that its length matches the expected length for the country, and (2) that the two check digits pass a MOD-97 algorithm. A valid IBAN is correctly formatted; it doesn't confirm the account exists or is active.

Question 2

How does IBAN validation work?

Accepted Answer

The validator moves the first 4 characters to the end of the IBAN, replaces each letter with a number (A=10, B=11 ... Z=35), then computes the remainder when dividing the resulting number by 97. If the remainder is 1, the IBAN is valid. The two digits in positions 3–4 are the check digits that make this work.

Question 3

My IBAN passes validation — does that mean the account exists?

Accepted Answer

No. Validation only confirms that the IBAN is correctly formatted and the check digits are mathematically correct. It does not check whether the account is open, active, or belongs to who you think it does. Only the receiving bank can confirm an account exists.

Question 4

Which countries use IBANs?

Accepted Answer

Over 80 countries use IBANs, including all EU member states, the UK, Norway, Switzerland, Turkey, Saudi Arabia, UAE, Pakistan, and many others. The US, Canada, Australia, and most of Asia and Africa do not use the IBAN system — they use routing numbers, SWIFT/BIC codes, or BSB numbers instead.

Question 5

What is the BBAN in an IBAN?

Accepted Answer

BBAN stands for Basic Bank Account Number — it's the part of the IBAN after the 2-letter country code and 2 check digits. The BBAN format varies by country: it typically encodes a bank code, branch code (sort code), and the individual account number.

Question 6

Why does my IBAN show as invalid?

Accepted Answer

Common reasons: (1) a digit or letter was mistyped, (2) the IBAN is the wrong length for that country, (3) the check digits don't match the rest of the number, or (4) you've pasted part of a longer reference number instead of the IBAN itself. Try re-copying directly from your bank statement or internet banking portal.

Question 7

Is my IBAN data stored or shared?

Accepted Answer

No. The validation runs entirely in your browser using JavaScript — nothing is sent to our servers. Your IBAN never leaves your device.

IBAN validator

IBAN validator — questions & answers