Invoicing GitHub Repositories (2026) · Open Source Tools

💵 Independent financial accounting with intelligent reporting, alternative to Quickbooks, Xero, Wave.

Dolibarr ERP CRM is a modern software package to manage your company or foundation's activity (contacts, suppliers, invoices, orders, stocks, agenda, accounting, ...). it's an open source Web application (written in PHP) designed for businesses of any sizes, foundations and freelancers.

Ever® Gauzy™ - Open Business Management Platform (ERP/CRM/HRM/ATS/PM) - https://gauzy.co

BottleCRM: free, open-source (MIT) CRM with sales, support tickets and invoicing in one app. Unlimited users; self-host or use the hosted app.

All in One PSA for MSPs, which Unifies client, contact, vendor, asset, license, domain, ssl certificate, password, documentation, file, network and location management with ticketing and billing capabilities, with a client portal on the side.

Ubilling is an open-source billing system designed for Internet service providers (ISPs). It provides tools for managing subscribers, handling payments and creating detailed reports. Ubilling allows control and monitoring of a wide range of network equipment and can be easily extended with custom functionality.

Sell-Your-Saas is an Open Source solution to automate and sell any Web application as a SaaS service. Solution supports the deployment/undeployment of any application, customer dashboard, automatic invoicing and payment (credit card or sepa direct debit), management of a reseller network, security, backup, supervision and more...

Invoicerr is a freelance-focused invoicing app that lets you create quotes, generate invoices, track payments, and collect secure signatures.

Selbst gehostete Buchhaltung für Freiberufler, Selbstständige, Kleinunternehmer, GmbH und UG: E-Rechnung (ZUGFeRD, XRechnung), Belege, Bankabgleich, EÜR oder Bilanz, E-Bilanz und Steuererklärungen an ELSTER. Für die GoBD gebaut, DATEV-Export. Open-Source-Alternative zu Lexware Office (lexoffice) und sevDesk. Docker-Image für den eigenen Server.

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

Miru | Time Tracking and Invoicing and Employee Benefits. Built using Ruby On Rails and ReactJS

🧾 Open-source WHMCS alternative — self-hosted hosting billing & client portal. Laravel 13 + MySQL. Invoicing, domains, SSL, tickets, reseller, multi-language (30 locales), 16 themes. Free & MIT-licensed. Docs: https://docs.pnlcs.com

Kimai is the #1 open-source time-tracking application. From freelancers to companies and organisations - everyone can manage timesheets, generate reports, create invoices and so much more... Web-based multi-user application, available as On-Premise or SaaS version: https://www.kimai.org

Simple and elegant invoicing solution.