field1 rules
Every EN 16931, Peppol and XRechnung rule that constrains BT-7. 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-CO-03 | fatal | Value added tax point date (BT-7) and Value added tax point date code (BT-8) are mutually exclusive. |
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.