LU · ISO 13616
Luxembourg IBAN — format, length, example & validator
IBANs issued in Luxembourg are 20 characters long and begin with the country code LU. Validate a Luxembourg IBAN below, or read on for the full structure, an example, and how the MOD 97 check digits work.
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How a Luxembourg IBAN is structured
A Luxembourg IBAN is read left to right: a 2-letter ISO 3166 country code (LU), 2 MOD 97 check digits, then a 16-character BBAN. The BBAN is split into 2 fields: 3 digits, 13 characters.
Luxembourg IBAN example
A sample Luxembourg IBAN that passes all checks (format, length, MOD 97):
How Luxembourg IBAN check digits work
The two digits at positions 3–4 are a MOD 97-10 checksum computed from the country code and the BBAN. To verify it, the IBAN is rearranged (BBAN first, country code and check digits last), letters are converted to numbers (A = 10, B = 11, …), and the whole integer is taken mod 97. A valid IBAN has a remainder of 1. This catches any single-digit typo and most transposition errors — which is why a one-character mistake is enough to make a Luxembourg IBAN fail validation instantly.
Luxembourg IBAN FAQ
- How long is a Luxembourg IBAN?
- A Luxembourg IBAN is always 20 characters long: 2 letters for the country code (LU), 2 check digits, and a 16-character BBAN. Any Luxembourg IBAN that is shorter or longer than 20 characters is invalid.
- What country code does a Luxembourg IBAN start with?
- A Luxembourg IBAN starts with the ISO 3166 country code LU. The first two characters are always LU, followed by two MOD 97 check digits, then the country-specific BBAN.
- How do I validate a Luxembourg IBAN?
- Paste the IBAN into the validator on this page — it checks the character set, the 20-character length, and the MOD 97 check digits, all in your browser. You can also open the full IBAN validator with a Luxembourg example pre-filled.
- Does a valid Luxembourg IBAN mean the account exists?
- No. Validation only confirms the IBAN is structurally well-formed and the check digits are correct per ISO 13616. It does not verify the account exists, is open, or belongs to anyone. Always confirm with the recipient or their bank before sending money.
⚠️ Validation only checks structure and check digits against ISO 13616. A valid Luxembourg IBAN does not guarantee the account exists or is open. Always confirm with the recipient or their bank before initiating a transfer.