UBL-CR-646
Syntax rules enforced by XRechnung · severity: error · in EN 16931 (UBL) · an error in XRechnung (KoSIT configuration), only a warning in plain EN 16931
A UBL invoice should not include the InvoiceLine SubInvoiceLine
What it means
Sub-invoice lines (SubInvoiceLine) aren't allowed in a standard XRechnung; list them as normal invoice lines. Only the XRechnung extension allows them.
How to fix it
Open the invoice in your invoicing software or XML, correct the fields named in the rule, and check the file again. Our free validator shows exactly where in the file the rule failed. If you need a new compliant invoice, you can create one for free.