European Union
EU-level open source clusters around two things every business touches: VAT number validation against VIES, and the EN 16931 e-invoicing standard that ViDA will push into every member state. Libraries here handle MOSS/OSS VAT rules, structured invoice formats, and cross-border compliance so national tools don't have to.
ViDA is about to make digital reporting mandatory across the union, and there is no open reference implementation of the new requirements yet — the first good one will be everywhere.
12 projects tagged European Union, ranked by community stars.
Handle all the hard stuff related to EU MOSS tax/vat regulations, the way it should be.
Open Source Java e-Invoicing library, validator and tool (Factur-X/ZUGFeRD, UNCEFACT/CII XRechnung)
Python lib for Factur-X, the e-invoicing standard for France and Germany
Component using the European Commission (EC) VAT Information Exchange System (VIES) to verify and validate VAT registration numbers in the EU, using PHP and Composer.
Validation artefacts for the European eInvoicing standard EN 16931
Create and import e-invoices with ERPNext.
Libreoffice Extension to generate PDF Factur-X invoices with Libreoffice Calc
Java library helping you to handle ZUGFeRD invoices
Official Model Context Protocol (MCP) server for vatnode — EU VAT validation, rates, and format checks for AI agents (Claude, Cursor, ChatGPT).
VAT ID validateion MCP server using https://ec.europa.eu/taxation_customs/vies/