SolidInvoice — Open Source Invoicing Software for $8/mo | WarmIndex

SolidInvoice is a professional open-source invoicing application for freelancers and small businesses, available to self-host for free or via cloud hosting for $8/month.

🚀 Overview

SolidInvoice is a sophisticated, open-source invoicing platform that simplifies billing for freelancers and small businesses. It offers an elegant interface for creating invoices, quotes, managing clients, and processing payments.

This project solves the problem of complex and costly invoicing software by providing a powerful, customizable, and free self-hosted alternative that accelerates payments through online integrations and automation. It's built for freelancers, solopreneurs, and growing teams who need professional tools without vendor lock-in or high fees.

We built it to deliver a simple, elegant solution that's fully open-source, actively maintained, and flexible for both technical users (self-hosting) and non-technical ones (cloud option).

✨ Key Features

Client Management: Organize clients with contacts, notes, multiple addresses, and activity tracking for better relationship management.
Invoices & Quotes: Create professional, branded invoices and quotes with accurate totals, taxes, discounts, and multi-currency support.
Recurring Billing: Automate subscriptions and repeat invoices with custom cycles, proration, and automatic reminders.
Payment Integrations: Accept online payments via Stripe, PayPal, or offline methods with automatic status updates and reconciliation.
Team Collaboration: Invite team members, assign roles and permissions for secure multi-user access.
REST API: Integrate with other tools for custom workflows. Optional: Enterprise security, daily backups (cloud), notifications (email, text).

🛠 Tech Stack

Frontend: Twig templates, HTML/SCSS, TypeScript, Bun, Webpack
Backend: PHP, Symfony framework, API Platform
Database: MySQL/MariaDB or PostgreSQL (via Doctrine ORM)
Auth: Symfony Security (custom)
Hosting: Docker, FrankenPHP, self-hosted or SolidInvoice cloud

👥 Who Is This For?

This project is useful for:

Freelancers who want to get paid 2x faster with online payments, recurring billing, and automated reminders
Small businesses looking for comprehensive client and invoice management without high costs
Teams and indie makers building custom invoicing solutions via API and self-hosting

📸 Screenshots / Demo

Live demo: https://solidinvoice.co (sign up for 30-day free trial, no credit card required)
GitHub: https://github.com/SolidInvoice/SolidInvoice

🔥 Project Status

🟢 Actively building

Last updated: 2026-03-24

❓ FAQ

Is this project free?

Freemium: Fully open-source and free to self-host with all features; cloud hosting starts at $8/month with a 30-day free trial (no credit card required). (Explain briefly.)

Is the source code available?

Yes — https://github.com/SolidInvoice/SolidInvoice (MIT License)

Can I contribute?

Yes — star/fork the repo, report issues, submit pull requests, or share feedback via GitHub discussions or the contact form. Join 24 contributors in keeping it maintained.