Validate ZUGFeRD — Mustang reference engine, every profile.
Drop a ZUGFeRD invoice. Mustang checks the embedded CII XML against EN 16931 (BASIC / EN 16931 / EXTENDED), detects legacy 1.0 files automatically, and the PDF/A-3 carrier is validated alongside.
ZUGFeRD (Zentraler User Guide des Forums elektronische Rechnung Deutschland) is the German hybrid e-invoice standard, maintained by FeRD since 2014. Like Factur-X — which it is technically merged with from 2.1 onward — it pairs a PDF/A-3 with embedded UN/CEFACT CII XML. Current version: ZUGFeRD 2.3 (2024) with XRechnung-aligned EXTENDED profile.
Frequently asked questions
What is ZUGFeRD?
ZUGFeRD is the German national hybrid e-invoice format: one file that is both a PDF/A-3 invoice and a structured CII XML document. The XML is embedded inside the PDF as an attachment named ZUGFeRD-invoice.xml (1.x) or factur-x.xml (2.x). Maintained by FeRD (Forum elektronische Rechnung Deutschland), fully aligned with EN 16931 from version 2.1.
How is ZUGFeRD different from XRechnung?
XRechnung is a pure-XML format (no PDF carrier) used for B2G invoicing to German federal and state authorities. ZUGFeRD is hybrid — PDF/A-3 plus embedded XML. ZUGFeRD 2.3's EXTENDED profile is feature-compatible with XRechnung. Choose XRechnung if your receiver only accepts the routing portal; choose ZUGFeRD if you also want a human-readable PDF.
Does this validator support ZUGFeRD 1.0 (legacy)?
Yes. Mustang detects the version from the embedded XML namespace and applies the matching profile. ZUGFeRD 1.0 (published 2014, attachment ZUGFeRD-invoice.xml, namespace urn:ferd:CrossIndustryDocument:invoice:1p0) is validated against its original schema; ZUGFeRD 2.x is validated against EN 16931. Files that mix the two get a clear error.
Is ZUGFeRD accepted for German B2G e-invoicing?
Yes — ZUGFeRD 2.x in the XRECHNUNG profile is accepted by the federal portal (ZRE) and most Bundesländer portals (e.g. OZG-RE). For B2B, Germany's E-Rechnungsgesetz mandates structured e-invoices for all domestic B2B transactions starting 2025, with full receive-capability obligations from 2026. Both ZUGFeRD and XRechnung are compliant.