SolidInvoice is an MIT-licensed, self-hostable invoicing and billing platform built on Symfony and PHP for freelancers and small businesses that want to send quotes and invoices without handing their client data to a subscription SaaS.

What it is

SolidInvoice is an open-source billing application that covers the full quote-to-payment cycle: quotes that convert into invoices in one click, recurring invoices on flexible schedules, multi-currency amounts, multi-tax handling, PDF generation, overdue detection, and payment reminders. It runs on Symfony 7.1 and PHP 8.4, uses Doctrine ORM for persistence, API Platform 4 for its REST API, and Tabler UI on Bootstrap 5.3 for the interface. The codebase ships as one product with two delivery paths — free self-hosted under MIT, or hosted by the maintainers at a flat $8 per month — and both ship the same codebase and feature set.

The concrete thing it replaces is the locked-in invoicing subscription. Most invoicing tools force a choice between usability and data ownership; SolidInvoice is designed so a freelancer or small business can run the billing stack on their own server and still get the features normally reserved for paid tiers, including per-client currency, custom fields for clients and contacts, role-based access control, and multi-tenancy for running several companies from a single install. It lives in the PHP and Symfony ecosystem, so teams already comfortable with that stack can extend, integrate, and operate it with familiar tooling.

Key capabilities

• Quote-to-invoice conversion in one click, plus recurring invoices on flexible schedules.
• Multi-currency support using real Money objects rather than floats, with multi-tax support, invoice-level tax, and automatic rate snapshot on issue.
• 8 built-in PDF templates for invoices and quotes, plus per-line discounts and flat-rate or percentage tax types.
• Invoice state machine moving through draft, pending, and paid, with automatic overdue detection and configurable payment reminders.
• REST API powered by API Platform 4 exposing JSON-LD, JSON-HAL, JSON, and XML, authenticated with a token sent in the X-API-TOKEN header.
• Payment gateways brought in through Payum, including Stripe and PayPal, with online payment links and PCI-compliant handling where no card data touches the server.
• Built-in MCP server with OAuth2 for AI agent automation, Meilisearch for full-text search, 2FA via TOTP, and Google OAuth login.
• Deployment tooling including Helm charts for Kubernetes and opt-in Prometheus metrics, with Symfony Messenger for async task processing.

Who uses it and how

• Freelancers who need to send a quote, convert it to an invoice, and collect payment online without paying per client.
• Small businesses running several legal entities or brands, using the built-in multi-tenancy and per-client currency, addresses, and contact channels.
• Privacy-first teams and self-hosting tinkerers who want the database, encrypted secrets, and exports under their own control.
• Kubernetes operators deploying via the provided Helm charts and wiring opt-in Prometheus metrics into existing monitoring.
• Teams automating billing workflows through the REST API or the MCP server, for example generating invoices or querying clients from an agent.
• Organizations that would rather not run infrastructure at all, using the hosted option at $8 per month with automatic updates and managed daily backups.

Getting started

Run the published container with docker run -p 8080:80 solidinvoice/solidinvoice, or sign up at solidinvoice.co for the hosted version. Configuration options and the full image details are documented on Docker Hub under solidinvoice/solidinvoice.

How it compares

No competing products are named in the material provided, so SolidInvoice stands alone in this registry. The only comparison the project itself draws is internal: self-hosted versus hosted, where the self-hosted build is free forever under MIT with manual updates and self-managed backups, and the hosted build costs a flat $8 per month with automatic updates, managed daily backups, and branding removed, while data ownership and export remain available in both.

When to use it — and when not to

A self-hoster must operate the application server, a database, and backups, and must handle updates manually, so teams without anyone willing to own that maintenance should take the hosted plan instead. Anyone needing per-seat or enterprise vendor support contracts will not find them here, and the project carries 190 open issues, which is worth weighing before committing to it for critical billing. The MIT licence and full data export keep the exit path open, which offsets much of that operational risk.

docker run -p 8080:80 solidinvoice/solidinvoice

brew install solidworx/tap/solidinvoice
solidinvoice run

chmod +x solidinvoice
./solidinvoice run

git clone https://github.com/SolidInvoice/SolidInvoice.git
cd SolidInvoice
composer install
bun install && bun run dev

bun run build