E-invoicing standards & validation rules

covered · 10 open projects

E-invoice formats, validation artefacts, national extensions and integration guides.

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The official German validator and the EN 16931 artefacts it checks against.

Project	Kind	Jurisdiction	Last update	Stars
KoSIT validatorGermany's official validator engine for XML e-invoices: checks XSD and Schematron, then reports.	APIs	DE · EU	Aug 2026	185
eInvoicing-EN16931Validation artefacts for EN 16931, the European e-invoicing standard.	APIs	EU	Apr 2026	257
Dutch Peppol Authority validationSchematron and XSL validation artefacts for SI-UBL and NLCIUS e-invoices from the Dutch Peppol Authority.	APIs	NL	Jul 2026	26
KSeF official clients (C#, Java)Official C# and Java clients for KSeF, Poland's national e-invoice system, from the Ministry of Finance.	APIs	PL	Sep 2026	112
ksef-apiIntegration guide for KSeF 2.0, Poland's national e-invoicing system.	APIs	PL	Sep 2026	223
ksefujValidator for Polish KSeF FA(3) e-invoices: XSD, business rules and tax maths, as web app, npm and CLI.	APIs	PL	Aug 2026	—
NAV Online InvoicePublic repository of Hungary's Online Invoice real-time reporting system: schemas, docs and examples.	APIs	HU	Feb 2026	177
Peppol BIS Billing 3.0Specification and validation rules for Peppol BIS Billing 3.0 e-invoices, from OpenPeppol.Licence unknown	APIs	EU	Mar 2026	—
phive-rulesE-invoice validation rules for the phive engine, covering many countries.Licence unknown	APIs	Global	Oct 2026	—
XRechnung validator configurationThe official XRechnung and EN 16931 validation scenarios for the KoSIT validator.	APIs	DE · EU	Sep 2026	116

Every project here is maintained and serves a tax authority. See the team's projects in the list.