BR-DE-22 — E-Invoice Validation Rule & Fix

Fixture ID: duplicateAttachmentNames · XPath: /ubl:Invoice/cac:AdditionalDocumentReference[2]/cac:Attachment/cbc:EmbeddedDocumentBinaryObject

1. Why This Rule Triggers (Diagnostic Message)

Two embedded attachments carry the same filename "a.pdf" — supportingDocuments[0] and supportingDocuments[1]. XRechnung requires the filename attribute of every EmbeddedDocumentBinaryObject to be unique, because the receiving system writes the attachments out to one directory: a duplicate name means one document silently overwrites the other, and the one that survives is whichever the parser happened to reach last.

2. How to Fix BR-DE-22

Rename one of them. Prefix with the reference (BT-122) or an index — "2026-000142-anlage-1.pdf", "2026-000142-anlage-2.pdf" — so the names stay unique even when two attachments genuinely are the same kind of document.

3. Valid Code / Payload Example

"attachment": { "filename": "2026-000142-stundennachweis.pdf", "mimeCode": "application/pdf", "content": "JVBERi0xLjQK" }