Download the latest validation artefacts release from the ConnectingEurope/eInvoicing-EN16931 GitHub repository (current release v1.3.16 as of 2026-04-10)
Select the syntax-appropriate schematron: UBL 2.1 or CII D16B, found under ubl/schematron/ or cii/schematron/ respectively
Compile the .sch file to XSLT using a Schematron processor such as Saxon or the pre-compiled .xslt files included in the release
Apply the compiled XSLT to your invoice XML and capture the SVRL output
Parse SVRL for failed-assert elements; treat any BR-* rule failures as blocking errors and flag W-* rules as warnings
Known gotchas
The repository ships both abstract and syntax-bound schematrons; always use the syntax-bound version for your format, not the abstract model file
Country-specific CIUS (e.g., XRechnung, RO_CIUS) add additional schematron layers on top of EN 16931 — run both layers in sequence
Schematron releases lag behind mandate updates; subscribe to repository releases to catch breaking corrections ahead of enforcement deadlines
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