E-invoice validation rules, in plain language

When an e-invoice is refused, the check names a rule number and nothing else. This is what the number means, why files fail it, and what to change.

These 20 are the rules real invoices break most often. That was measured rather than guessed: a valid invoice was broken in 28 different ways that invoices are genuinely wrong in practice, and every one was put through the official validator.

German additional rules (XRechnung)

European norm EN 16931

Your rule is not here? Run your file through the validator. It names every rule the file breaks, including the ones without a page yet.