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Compliance Guides

docs101 is built from the ground up to help you stay compliant with European invoicing standards and regulations. Every invoice you generate is automatically produced in ZUGFeRD/Factur-X format, validated against EN 16931, and ready for seamless digital exchange.

What's Inside​

  • Country Availability & E-Invoicing Requirements — Find out where docs101 works today, which EU countries have e-invoicing mandates, and what cross-border and ViDA rules mean for your business.

  • ZUGFeRD & Factur-X — How docs101 generates hybrid PDF+XML invoices, what data is embedded, and how validation works end-to-end.

  • EU Compliance — EN 16931, VAT handling, VIES validation, reverse charge, and what you need to configure for your country.

  • PDF Validation Tool — A free, public tool for validating any ZUGFeRD/Factur-X PDF. No login required — upload a PDF and get a detailed compliance report.

Key Compliance Features​

docs101 automatically handles:

  • ZUGFeRD/Factur-X XML generation — Every invoice embeds a machine-readable XML file conforming to the ZUGFeRD/Factur-X standard
  • KOSiT validation — The generated XML is validated against the official KOSiT validator to ensure EN 16931 compliance
  • PDF/A-3 compliance — Invoice PDFs are produced in PDF/A-3 format as required by ZUGFeRD
  • VAT calculation and categorization — Correct VAT rates and categories (standard, reverse charge, intra-community, export, exempt) applied automatically
  • VIES VAT number validation — EU VAT numbers are verified against the official VIES database
Free PDF Validation Tool

docs101 provides a public PDF validation tool that anyone can use — no account or login needed. Upload any ZUGFeRD or Factur-X PDF to check XML embedding, KOSiT compliance, and PDF/A metadata. Learn more in the PDF Validation Tool guide.

For Your Tax Advisor​

When sharing invoices with your tax advisor or accountant, the ZUGFeRD/Factur-X format means they can:

  • Import invoices directly into accounting software
  • Automatically extract all structured data (amounts, VAT breakdowns, payment terms)
  • Validate compliance status using the embedded XML
  • Work with both the visual PDF and machine-readable XML simultaneously

Getting Started​

Start by checking the Country Availability guide to see if docs101 covers your country. Then review the ZUGFeRD & Factur-X guide to understand how docs101 generates and validates compliant invoices, and explore EU Compliance for configuration details specific to your business. If you want to verify existing invoices, head directly to the PDF Validation Tool.

Need help? Check our FAQ or contact support.