BR-DE-26

The rule applies to invoices and credit notes. If the invoice type code (BT-3) or credit note type code is set to 384 (corrected invoice), the rule expects at least one preceding invoice reference element (cac:BillingReference/cac:InvoiceDocumentReference) to be present. Because this is a warning, the validator reports it but the document is not rejected; the rule is advisory and recommends that corrected invoices carry a reference to the preceding invoice.

If the document uses type code 384, add at least one cac:BillingReference/cac:InvoiceDocumentReference element to the invoice. The test only checks that this element exists, so ensure the element is present and populated with the appropriate preceding invoice reference details.