Authority
KoSIT (Coordination Office for IT Standards)
Definition
The Coordination Office for IT Standards (KoSIT) is an institution of the Free Hanseatic City of Bremen that develops and maintains IT standards for public administration on behalf of the IT Planning Council of Federal and State Governments. KoSIT is responsible, among other things, for maintaining the XRechnung standard, the open-source Validator tool, and operating the national Peppol infrastructure in Germany.
Background & context
KoSIT is organisationally located within the Free Hanseatic City of Bremen and acts on behalf of the IT Planning Council, the central body of the federal and state governments for steering federal IT. Its task is the development, maintenance and provision of IT standards for public administration. In the e-invoicing field, KoSIT is the authoritative body: it maintains the XRechnung standard including the Schematron business rules (EN 16931 and BR-DE rules), regularly publishes new versions and provides the official, open-source 'KoSIT Validator', which serves as the reference implementation for checking e-invoices. KoSIT also acts as the German Peppol Authority and coordinates the national Peppol infrastructure. Anyone generating an XRechnung should follow the respective current KoSIT publications, as these define the binding validation rules and CustomizationIDs.
In practice — a worked example
A software vendor wants to ensure its invoicing module produces valid XRechnung documents. It downloads the open-source KoSIT validator and the current test scenario (the 'validator-configuration-xrechnung') and checks its test invoices automatically. If the report recommends 'accept', the document meets the rules of the current XRechnung version. On a new XRechnung release by KoSIT (e.g. from 2.3 to 3.0), it updates the configuration and CustomizationID, because the receiving portals reject the old version once the transition period ends.
Common mistakes
- •Running the KoSIT validator without the matching configuration file — the actual check rules sit in the separate validator-configuration, not in the validator itself.
- •Using outdated Schematron/configuration versions: after a KoSIT update, previously valid invoices may suddenly throw errors.
Frequently asked questions
Is the KoSIT validator free?
Yes, the KoSIT validator is open source and freely available. It is the official reference implementation; many commercial tools implement the same rules.
Who defines the XRechnung rules?
KoSIT maintains the XRechnung specification and the associated Schematron business rules on behalf of the IT Planning Council. It publishes the binding versions.