Reference
Markdown exportKoSIT
German coordination body; commonly refers to the BR-DE validation rules/validator for XRechnung.
Definition
German coordination body; commonly refers to the BR-DE validation rules/validator for XRechnung.
Why this term matters
KoSIT publishes the official validator and Schematron rule sets that German federal/state portals (ZRE, OZG-RE) execute on every incoming XRechnung. Reproducing KoSIT validation locally before sending is the single most effective way to avoid B2G rejections and downstream cash-flow delays.
Explanation
Validation errors are commonly referenced by BR-DE rule IDs.
Useful for troubleshooting why an invoice is rejected.
Common mistakes
Use these points as the practical checks for this section.
- Validating against the wrong KoSIT scenario — XRechnung-UBL-Invoice and XRechnung-CII have separate Schematron rules; using the UBL ruleset on a CII document hides BR-CO/BR-DE failures.
- Running an out-of-date validator JAR — KoSIT releases follow XRechnung versions (e.g. 1.5.x for XRechnung 3.0.x), and old JARs miss new BR-DE rules.
- Treating warnings as informational — many BR-DE warnings (e.g., suspicious BT-32 SellerTaxRegistrationIdentifier formats) become hard errors in the next XRechnung minor.
- Not bundling the EN 16931 codelist files with the validator — codelist mismatches surface as cryptic CL-* failures rather than business-rule errors.
Frequently asked questions
Is the KoSIT validator free?
Yes — KoSIT publishes the validator and rule sets under the Apache 2.0 licence on GitHub (itplr-kosit/validator and itplr-kosit/validator-configuration-xrechnung). It is the same engine ZRE/OZG-RE run server-side.
How do I read a KoSIT report?
KoSIT outputs an XML report with a top-level acceptance result and per-rule failedAssert entries. Each entry references the rule ID (BR-*, BR-DE-*, BR-CO-*), location (XPath), and a human-readable message — the rule ID is the key to look up the spec.
Does KoSIT cover Peppol BIS Billing 3.0 too?
KoSIT focuses on XRechnung. For Peppol BIS Billing 3.0 you should additionally run the OpenPEPPOL Schematron rules (PEPPOL-EN16931-*). Many German recipients accept either profile and validate accordingly.