warningEN 16931syntax binding ruleUBL
A UBL invoice should not include the PaymentTerms InstallmentDueDate
The element 'PaymentTerms InstallmentDueDate' is present, but it carries no meaning in the EN 16931 semantic model, so a receiver is free to ignore or reject it.
Remove 'PaymentTerms InstallmentDueDate' from the document. Look for cac:PaymentTerms/cbc:InstallmentDueDate — that is the exact location. Nothing in EN 16931 maps to it - it is almost always left over from a generic UBL template. Reported as a warning.
UBL — context /ubl:Invoice | /cn:CreditNote
not(cac:PaymentTerms/cbc:InstallmentDueDate)
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.