How long is a Luxembourg IBAN?

A Luxembourg IBAN is exactly 20 characters: the country code LU, two check digits, a 3-digit bank code, and a 13-character account number. Any other length is rejected.

What identifies the bank in a Luxembourg IBAN?

The 3-digit numeric bank code after the check digits identifies the institution (for example 001 for BCEE or 111 for POST Luxembourg). It is short because Luxembourg has a compact banking sector.

How does the MOD-97 checksum work?

The first four characters (LU plus the check digits) move to the end, each letter expands to a two-digit number (A=10 to Z=35), and the result is divided by 97. The IBAN is valid only when the remainder is 1.

Does a pass mean the account exists?

No. It confirms the format and checksum only. The account could still be closed or belong to someone else; only the bank can confirm that.

Yes. The validator runs entirely in your browser. Your IBAN is never uploaded, stored, or logged, so it is safe for confidential details.

Luxembourg IBAN Validator

Luxembourg IBANs are short at 20 characters, with a compact 3-digit bank code reflecting the country’s small but globally significant banking sector. As a major hub for European fund administration and private banking, Luxembourg sees heavy SEPA traffic, and a single wrong digit means a bounced transfer. This validator splits the IBAN into its fields and runs the ISO 7064 MOD-97-10 checksum before you submit a payment.

Paste any IBAN starting with LU and the tool validates it locally in your browser.

How it works

A Luxembourg IBAN has four parts:

Country code — the fixed letters LU
Check digits — two digits from the MOD-97 algorithm
Bank code — three digits identifying the bank (for example 001, 002, 111)
Account number — 13 alphanumeric characters

The checksum moves the first four characters to the end, replaces each letter with its numeric value (A=10 through Z=35), and divides by 97. A remainder of exactly 1 means the IBAN is valid. The tool folds the modulus one digit at a time so the long number never overflows.

Tips and notes

A length other than 20 fails immediately — the most common paste error.
The 3-digit bank code is numeric for Luxembourg, unlike the Gulf IBANs that use letters.
A valid checksum confirms format only. Use the iban-bic-lookup-tool to derive the matching BIC.