KF-FR-TVA: The French VAT number check digits are wrong
This code shows up when an electronic invoice is validated. Here is what it means, why it fires, and what to change in the file.
Why this code appears
A French VAT number is FR, two check characters, then the nine digits of the SIREN. The numeric key is derived from the SIREN: copying the SIREN without the key, or making up two digits, produces a number the tax administration refuses.
How to fix it
Use the number exactly as it appears on your VAT registration notice. The numeric key is (12 + 3 × (SIREN modulo 97)) modulo 97, on two digits.
Where it happens
This check is ours, not a code from the standard: we do not cover enough of EN 16931 to borrow its numbers, and a misattributed official code would send you to fix the wrong field. It concerns BT-31.