BT-1 — Invoice number

field1 rules

Every EN 16931, Peppol and XRechnung rule that constrains BT-1. If one of them fails, the others are usually worth a look — a wrong value in one field tends to break several checks at once.

BR-02

fatal

An Invoice shall have an Invoice number (BT-1).

All rules

Check an invoice against every BT-1 rule

…or paste the XML instead

Nothing is stored, and the whole invoice is checked, not just this rule. A PDF only works if it is Factur-X / ZUGFeRD — a PDF with the invoice XML inside it.