Validate Factur-X — Mustang reference engine, every profile.
Drop a Factur-X invoice (PDF with embedded CII XML). Mustang checks EN 16931 conformance across MINIMUM / BASIC WL / BASIC / EN 16931 / EXTENDED; PDF/A-3 carrier is validated in parallel.
Factur-X is the French–German hybrid e-invoice standard developed jointly by FNFE-MPE (France) and FeRD (Germany), first published in 2017. It pairs a human-readable PDF/A-3 invoice with an embedded UN/CEFACT CII XML — one file for both back-office automation and human approval. Fully aligned with EN 16931.
Frequently asked questions
What is Factur-X and how is it different from a normal PDF invoice?
Factur-X is a hybrid invoice: simultaneously a PDF/A-3 (archival, looks like paper, readable by humans) and a structured CII XML (so a finance system parses line items, totals, VAT codes without OCR). The XML lives as an embedded attachment inside the PDF/A-3 wrapper. The file is one and the same — software either renders the PDF or extracts the XML.
What's the difference between Factur-X and ZUGFeRD?
They are now the same standard under two brands. The technical spec (PDF/A-3 + CII XML at /Factur-X/factur-x.xml) is identical and produced jointly by FeRD and FNFE-MPE. 'Factur-X' is the French marketing name; 'ZUGFeRD' is the German one. From version 2.1 onward, the two are technically interchangeable.
Does Factur-X require PDF/A-3?
Yes, strictly. The PDF carrier must conform to PDF/A-3 (b or u variant) because it has to embed another file (the XML) and PDF/A-3 is the only PDF/A profile that permits attachments. If the PDF is PDF/A-1, PDF/A-2 or plain PDF, it is not a valid Factur-X document, even if the XML inside is perfect.
Is Factur-X mandatory for B2B invoicing in France?
Yes, in phases starting September 2026 under the réforme de la facturation électronique. All French B2B invoices must be issued in a Factur-X-compatible format (or pure UBL / CII) and routed via a PDP. For B2G (selling to the French state) e-invoicing has been mandatory since 2020 via Chorus Pro.