SolidInvoice

The application provides a web‑based system for creating and managing quotes, invoices, and client contacts, aimed at freelancers and small businesses that need to handle daily billing tasks. It supports online payment acceptance through services such as Stripe and PayPal, applies taxes and discounts, and can automate recurring billing and payment reminders. A RESTful API enables integration with other tools, and notifications can be sent via email, SMS, or HipChat.

Users can store full client histories, manage multiple addresses, and work with several currencies, making it suitable for international billing. Team members may be invited to collaborate on accounts, and the platform offers daily backups and GDPR‑compliant data handling. The software is released under the MIT license, can be self‑hosted on any PHP 8.4+ environment, and is also available as a Docker image for quick deployment.

The project is stable and open source, with a free tier for self‑hosting and an optional cloud offering at a flat monthly price. Documentation includes installation steps for Docker, archived packages, and source‑code deployment, and contributions are welcomed through a public repository.