Invoice Ninja is an open-source invoicing, time-tracking, and expense management platform built with Laravel and PHP, designed for freelancers, consultants, and small businesses that need professional billing tools without vendor lock-in. It combines invoice generation, payment processing, client portals, and project tracking in a single unified system.
The platform supports both hosted (SaaS) and self-hosted deployments, with full feature parity between them. It exposes a RESTful API, offers mobile and desktop apps for iOS, Android, macOS, Windows, and Linux, and integrates with Stripe, PayPal, GoCardless, and Zapier. The architecture follows Laravel conventions with repositories, services, events, and Fractal-based API responses, making it extensible for developers.
What You Get
- Professional Invoice Templates - 11 customizable invoice designs (4 free, 7 in Pro/Enterprise) with full branding control for logos, colors, and layouts.
- Multi-Gateway Payment Processing - Direct integrations with Stripe, PayPal, GoCardless, Authorize.net, Mollie, and BTCPay Server to accept credit cards, ACH, and crypto payments.
- Client Portal - Secure web portal for clients to view invoices, payment history, documents, and make one-click payments without logging into the admin dashboard.
- Time & Project Tracking - Built-in time-tracking and task management to log billable hours, associate them with invoices, and monitor project progress.
- Expense & Vendor Management - Track business expenses, categorize them, and link to vendors for streamlined accounting and reporting.
- API & Webhooks - Full REST API with documentation, webhooks for events like invoice creation, and Go SDK for custom integrations.
- Mobile & Desktop Apps - Native apps for iOS, Android, macOS, Windows, and Linux with offline sync and push notifications for payment alerts.
- Zapier & Make.com Integrations - Connect to 5,000+ apps to automate workflows like sending invoices when a Trello card is completed or logging expenses in Google Sheets.
- Self-Hosted with Docker & Cloudron - Deploy on your own server using Docker, Cloudron, YunoHost, Softaculous, or Elestio with full data control and no monthly fees.
- White-Labeling Option - $40/year license to remove Invoice Ninja branding from client-facing interfaces for agencies and resellers.
Common Use Cases
- Freelancers managing client billing - A graphic designer uses Invoice Ninja to create branded invoices, accept Stripe payments, and send automated late reminders—all from their phone.
- Small agencies tracking billable hours - A web development firm logs time per project, generates invoices with hourly rates, and syncs expenses to QuickBooks via Zapier.
- Consultants offering client portals - A financial consultant gives clients secure access to their portal to view invoices, download PDFs, and pay with PayPal without needing an account.
- Tech startups automating invoicing - A SaaS startup connects Invoice Ninja to Stripe and Zapier to auto-generate invoices when a customer’s trial ends or a subscription renews.
Under The Hood
Architecture
- Leverages Laravel’s modular architecture with dynamic module isolation, enabling features like Admin and Accounting to be enabled or disabled at runtime via configuration
- Enforces clean separation of concerns through distinct layers: Controllers manage HTTP flow, Services encapsulate business logic, Factories handle object creation, and Casts manage complex data serialization
- Employs dependency injection and the Strategy pattern to decouple payment processing and other core workflows, allowing extensibility without modifying core code
- Uses event/listener patterns for asynchronous system actions, ensuring non-blocking operations and loose coupling between components
- Integrates domain-specific compliance standards like ZUGFeRD and e-invoicing through dedicated packages, maintaining clear boundaries between financial models and regulatory logic
Tech Stack
- Backend powered by Laravel 12 with Octane for high-performance request handling, backed by Eloquent ORM and Scout for database and search operations
- Built on PHP 8.2+ with comprehensive support for major payment gateways including Stripe, Braintree, Square, and PayPal
- Frontend built with Vue 2, Laravel Mix, and Vite, utilizing Tailwind CSS with custom plugins for theming and responsive design
- Enhanced with modern JavaScript tooling, static asset optimization via PurgeCSS, and TypeScript support
- Infrastructure includes ElasticSearch for advanced document search and a robust testing ecosystem with Cypress and Sentry for monitoring
Code Quality
- Features an extensive test suite covering unit, feature, and integration scenarios with clear separation of concerns between test types
- Adheres to Laravel best practices with custom casts, repository patterns, and transformer layers that enhance maintainability and readability
- Maintains consistent naming conventions and descriptive identifiers across models, controllers, and tests
- Relies on PHPDoc annotations and typed method signatures for strong type safety, though domain-specific error handling could be more robust
- Implements a well-structured CI/CD pipeline with stubbed data for complex integrations like e-invoicing and PDF generation
What Makes It Unique
- Implements native multi-tenant data isolation using a custom MultiDB utility, enabling true SaaS scalability without schema duplication
- Features a dynamic form field mapping system that translates external inputs into internal models via configurable mappings, streamlining client onboarding
- Uses template-driven email and portal rendering with inline CSS and conditional HTML to ensure pixel-perfect delivery across clients without external dependencies
- Supports JSON-based design templates and factory-patterned rendering, allowing clients to customize invoice layouts without code changes
- Introduces referral earnings as a custom Eloquent cast that preserves type safety while serializing complex domain objects to JSON
- Provides unified payment gateway abstraction with dynamic metadata injection via Blade and client-specific configs, enabling real-time configuration without hardcoding