Invoice Ninja

Invoice Ninja is a battle-tested open-source invoicing platform that has been trusted by freelancers and agencies for years. The core appeal: full control over your data through self-hosting, complete transparency through open-source code, and flexibility to customize every aspect of your invoicing workflow. Unlike SaaS solutions, you own the infrastructure and can modify the software to fit your exact needs.\n\nThe platform supports quotes, invoices, recurring billing, expense tracking, and time logging—everything a services-based freelancer needs. Invoice Ninja integrates with 40+ payment gateways including Stripe, PayPal, and dozens of regional options. The free tier is genuinely useful (5 clients, unlimited invoices), and the Pro tier ($14/mo) removes limits. For indie hackers who value data ownership and customization, Invoice Ninja eliminates vendor lock-in fears.