Invoice Ninja
Invoice Ninja is an open-source invoicing solution that offers both a self-hosted and a cloud SaaS version. Users create proposals, invoices, and recurring billing schedules. Payment integrations allow clients to pay online. A built-in client portal centralizes invoices, quotes, and payment history. Advanced features include expense tracking, task management, and partial deposits. The open-source edition is free to install on your own server, while the hosted plan provides simpler setup. Invoice Ninja’s flexibility appeals to freelancers or small firms wanting custom branding and open-source freedom.