Standard
XRechnung
Definition
XRechnung is the German standard for structured electronic invoices in public sector procurement (B2G). It is based on the European standard EN 16931 and is available in two syntaxes: UBL 2.1 and UN/CEFACT CII. Since 27 November 2020, federal public buyers have been required to accept electronic invoices in XRechnung format, and state and municipal authorities have been progressively included.
Background & context
XRechnung is not a separate file format but a so-called CIUS (Core Invoice Usage Specification) — a national tightening of the European standard EN 16931. XRechnung restricts the standard (e.g. it makes some fields that are optional in EN 16931 mandatory) and adds German business rules (the BR-DE rules). An XRechnung can technically be serialised as either UBL 2.1 or UN/CEFACT CII; both syntaxes are equally valid. The standard is maintained by the Coordination Office for IT Standards (KoSIT) on behalf of the IT Planning Council and is updated roughly every six months (e.g. version 2.3, 3.0). An XRechnung can be recognised by its CustomizationID, e.g. `urn:cen.eu:en16931:2017#compliant#urn:xoev-de:kosit:standard:xrechnung_3.0`. The legal basis at federal level is the E-Invoicing Ordinance (ERechV) together with § 4a EGovG. Since 27 November 2020, federal suppliers have been required to invoice electronically in an XRechnung-compliant format; states and municipalities have adopted this in their own ordinances with partly differing effective dates.
In practice — a worked example
A Berlin IT service provider issues an invoice for €5,000 net to a federal ministry. From its accounting software it generates a UBL 2.1 file carrying the CustomizationID for XRechnung 3.0, enters the Leitweg-ID provided by the ministry into the BuyerReference field (BT-10), states its VAT ID in BT-31, and transmits the file via the ZRE portal using Peppol. The KoSIT validator checks the file automatically: it must pass both the UBL XSD schema and all EN 16931 and BR-DE Schematron rules. Only then is the invoice considered delivered and the clerk can approve it.
Common mistakes
- •PDF invoices sent by email do not count as an XRechnung — a PDF without embedded structured XML data does not satisfy the B2G obligation.
- •Missing or wrongly formatted Leitweg-ID (BT-10): without a correct buyer reference the invoice is not delivered by ZRE/OZG-RE (errors BR-DE-2/BR-DE-15).
- •Confusing XRechnung and ZUGFeRD: XRechnung is pure XML, while ZUGFeRD is a hybrid PDF/A-3 with embedded XML — both are EN 16931-compliant but technically different.
Frequently asked questions
Is XRechnung the same as a PDF invoice?
No. An XRechnung is a pure, structured XML file with no human-readable image layer. A PDF — even if it depicts an invoice — does not qualify as an XRechnung because the machine-readable data is missing. For visual display, XRechnung XML is typically transformed into HTML/PDF via an XSLT stylesheet.
Which XRechnung version do I have to use?
The version accepted by the recipient applies, identified via the CustomizationID. The ZRE and OZG-RE platforms publish which versions are actively supported. In practice you should always generate the most recent version permitted by the recipient (e.g. 3.0), as older versions are rejected after transition periods.
Should I use UBL or CII?
Both syntaxes are equally valid for XRechnung and are processed by the public receiving platforms. UBL 2.1 is more widespread in the B2G environment and identical to the Peppol BIS structure; CII is the basis of ZUGFeRD/Factur-X. The choice usually depends on what your software produces.
Does the XRechnung obligation also apply to B2B?
The XRechnung obligation in the narrow sense concerns B2G. In the B2B sphere, the Growth Opportunities Act requires EN 16931-compliant structured e-invoices from 2025 — XRechnung is a permitted but not the only format (ZUGFeRD/Factur-X in the EN 16931 profile is also allowed).