E-invoicing libraries for ZUGFeRD, Factur-X, XRechnung and Peppol in 2026

Commercial e-invoicing libraries for ZUGFeRD, Factur-X, XRechnung and Peppol

1. 1
   Pagero Pagero

   Discover e-invoicing, tax, legal and regulatory compliance solutions from Thomson Reuters, helping organisations navigate complexity with confidence.

   Integration Production-ready A company trading across several countries must send and receive structured e-invoices to meet mandates.

   77 readers a month Commercial
2. 2
   Avalara E-Invoicing Avalara

   Comply with international real-time reporting and e‑invoicing mandates. Automate financial operations with Avalara E‑Invoicing and Live Reporting.

   Integration Production-ready A multinational must comply with e-invoicing mandates in several countries and already uses Avalara for tax.

   Commercial

Open-source e-invoicing libraries for ZUGFeRD, Factur-X, XRechnung and Peppol

Complete systems you can adopt 1

1. 1
   Quba-viewer ZUGFeRD

   Quba is a viewer for electronic invoices

   Complete system Usable Someone in accounts receives XML e-invoices and needs to read and check them locally.

   ★ 206 Apache-2.0 Kotlin Active, pushed 10 days ago

Building blocks for your own system 9

1. 1
   Mustangproject ZUGFeRD

   Open Source Java e-Invoicing library, validator and tool (Factur-X/ZUGFeRD, UNCEFACT/CII XRechnung)

   Building block Production-ready A Java application must produce or check German or French e-invoices.

   ★ 483 Apache-2.0 XSLT Active, pushed 17 days ago
2. 2
   ZUGFeRD horstoeko

   ZUGFeRD/XRechnung/Factur-X Library

   Building block Production-ready You maintain a PHP app already using it; new projects should start with its successor, horstoeko/invoicesuite.

   ★ 437 MIT PHP Active, pushed 32 days ago
3. 3
   ZUGFeRD-csharp stephanstapel

   Open source C# e-invoicing library. Enables creating and reading ZUGFeRD invoices.

   Building block Production-ready Only for existing .NET projects that need a short bridge; new work should look elsewhere.

   ★ 395 Apache-2.0 C# Active, pushed 24 days ago
4. 4
   Phase4 phax

   phase4 - AS4 client and server for integration into existing systems. Specific support for Peppol and CEF eDelivery built-in.

   Building block Production-ready You are building a Peppol access point or another AS4 integration in Java.

   ★ 246 Apache-2.0 Java Active, pushed 3 days ago
5. 5
   Python-drafthorse pretix

   Pure-python ZUGFeRD implementation

   Building block Usable A Python application must emit ZUGFeRD invoices and the developer can work from the official specification.

   ★ 182 Apache-2.0 Python Active, pushed 5 days ago
6. 6
   ZATCA SallaApp

   An unofficial package maintained by Salla to help developers to implement ZATCA (Fatoora) QR code easily which required for e-invoicing

   Building block Usable A PHP system selling in Saudi Arabia must generate ZATCA-compliant invoices.

   ★ 168 MIT PHP Active, pushed 21 days ago
7. 7
   Factur-X atgp

   PHP library to manage your Factur-X / ZUGFeRD 2.0 PDF invoices files

   Building block Usable Your PHP system already produces PDF invoices and the XML, and needs to combine them into Factur-X files.

   ★ 154 MIT PHP Active, pushed 3 months ago
8. 8
   UBL Invoice num-num

   A modern object-oriented PHP library to read and create valid UBL and Peppol BIS files

   Building block Usable Your PHP app must send UBL invoices over Peppol, for example in Belgium.

   ★ 142 MIT PHP Active, pushed 13 days ago
9. 9
   Ph-ubl phax

   Java library for reading and writing UBL 2.0, 2.1, 2.2, 2.3, 2.4 and 2.5 documents

   Building block Production-ready A Java system handles UBL invoices, orders or other procurement documents.

   ★ 142 Apache-2.0 Java Active, pushed 7 days ago

All 19 open-source e-invoicing library projects

Compared head to head

Also under accounting software

Open-source licenses

• Permissive: 17. Use it anywhere, including in closed products. You keep the copyright notice; Apache-2.0 also grants patent rights.
• Strong copyleft: 2. If you distribute the program or anything built on it, you must release the whole source under the same license.

Languages

PHP 6, XSLT 5, Java 3, Kotlin 2, Python 2 and C# 1.