BR-DE-22

All attachments embedded in the invoice must carry distinct filenames. The filename is the only handle under which the recipient stores them.

Severity: Error
Applies to: CII, UBL
Rule set: v2026-01-31

Official rule text

Not all filename attributes of the embeddedDocumentBinaryObject elements are unique

Why it happens

The generator uses a constant name — every attachment is "anlage.pdf" or "attachment.pdf". With exactly one attachment this never shows; the second one triggers the error.

How to fix it

Give each attachment a unique name in the filename attribute (cac:Attachment/cbc:EmbeddedDocumentBinaryObject/@filename in UBL, ram:AttachmentBinaryObject/@filename in CII) — simplest is the file's original name, with a running number if needed.

NormAPI provides technical validation, not tax or legal advice.