Factur-X and ZUGFeRD: a PDF with the invoice inside

A Factur-X or ZUGFeRD file looks like an ordinary PDF. Inside it is a second invoice — the one software reads.

Two invoices in one file

The visible pages are a normal PDF. Attached inside the PDF is an XML file in the UN/CEFACT CII syntax, carrying the invoice's data. People read the page; accounting software books the XML.

In Germany the tax administration says it plainly: in a hybrid format the XML data is the leading part, and if it differs from the picture, the structured data wins (BMF letter of 15 October 2024, margin no. 31). That is why this site, when it opens such a PDF, compares the most important values from the data with the text on the page and tells you which ones it could not find.

Profiles

• EN 16931 and EXTENDED carry a full invoice under the European standard (EXTENDED adds more).
• BASIC carries a full invoice with fewer optional details.
• MINIMUM and BASIC WL carry only part of the invoice data. They are not EN 16931 invoices; Germany's tax administration excludes them from what counts as an e-invoice there (BMF letter, margin no. 30). This site says so before showing their content.

What we found in real files

In a test collection of 151 real hybrid PDFs, the attachment's name was not reliable (one correct invoice was called factur-y.xml) and the declared relationship to the PDF varied. So a reader should pick the invoice by its content, not by its file name — which is what this site does.

Facts on this page were checked against primary sources on 2026-10-21.