XMP metadata

Also called XMP, Factur-X XMP extension schema

XMP is the XML metadata block embedded in a PDF. Factur-X defines an extension schema carrying the document type, the attachment filename, the version and the conformance level, so software can tell the file is a Factur-X invoice without opening the attachment.

Format: XML metadata embedded in the PDF
Required fields: DocumentType, DocumentFileName, Version, ConformanceLevel
Overlaps with: BT-24 in the XML, which declares the same profile
Common failure: Present but incomplete, or disagreeing with BT-24

Four fields, and all of them are required

DocumentType, DocumentFileName, Version and ConformanceLevel. A file with some present and some missing usually had its metadata written by hand or by a partial template, and our validator reports that separately from the metadata being absent entirely.

The field that disagrees with the XML

ConformanceLevel is the profile, and the XML declares the same thing at BT-24. Nothing in a normal toolchain forces them to match.

We have watched this happen: Gotenberg will stamp a MINIMUM XMP onto EN 16931 XML and never complain. The file opens, and it contradicts itself. That is why our generator reads the profile back off the built XML rather than trusting the request, and why the validator reports the mismatch as its own finding.

Why it matters

It is how a receiving system discovers the file is Factur-X at all, before it decides to look for an attachment.
A mismatch between it and BT-24 produces a file that different receivers read differently, which is the worst kind of bug to debug.

Check it on your own file

Check the metadata and the XML agree
Both are read and compared, so a file that disagrees with itself is reported rather than passed.

Common questions

What is the Factur-X XMP extension schema?: A metadata block inside the PDF carrying DocumentType, DocumentFileName, Version and ConformanceLevel. It lets software identify the file as Factur-X and read its profile without opening the attachment.