Rules/EN 16931/Error
BR-03
Peppol BIS Billing 3.0.21An Invoice shall have an Invoice issue date (BT-2).
In plain English
The invoice has no issue date (BT-2).
How to fix it
Set cbc:IssueDate to the date the invoice was issued, as YYYY-MM-DD.
Check an invoice against every rule
One request returns each rule a document breaks, with this explanation and the fix.
All 1,103 rules
The full Peppol BIS Billing 3.0.21 rulebook, filterable.