Luxembourg TVA

What it covers

Returns a valid Luxembourg TVA (VAT identifier) with a correct two-digit check pair. Use `format=vat` for the LU-prefixed VAT number. Set `invalid=true` for a TVA with a deliberately wrong check pair.

A Luxembourg VAT number (numéro de TVA) is the letters LU followed by eight digits: a six-digit body and a two-digit check pair. It is the simplest checksum in the fleet — the check pair is just the body taken modulo 89.

How it’s calculated

The two-digit check pair is simply the six-digit body taken modulo 89, zero-padded to two digits.

Body = 123456.
123456 mod 89: 89 × 1387 = 123443, and 123456 − 123443 = 13, so the remainder is 13.
13 zero-padded to two digits = "13".

Edge cases

• The body’s first digit is drawn 1–9, so the six-digit body never has a leading zero.
• Because the check pair is body mod 89, it always lands in 00–88 — the pair 89–99 can never occur in a valid LU VAT number.
• A body that is an exact multiple of 89 gives check pair 00 (e.g. body 000089 → 00), which is valid, not a placeholder.

Gotchas

• The modulus is 89, not 97 (the IBAN/mod-97 family) nor 11 — using the wrong modulus is the classic mistake here.
• The check is over the six-digit body only; the LU country prefix is not part of the arithmetic.