FOSSBilling

FOSSBilling is free and open source billing and client management software for hosting businesses. It brings invoicing, service provisioning, domain management, and support ticketing into a single self-hosted system, so operators can manage clients and automate billing without vendor lock-in.

Automated Billing generates invoices, sends payment reminders, and supports multiple currencies with automatic exchange rate syncing. Hosting Provisioning works with cPanel, Plesk, DirectAdmin, HestiaCP, and other server managers. Domain Management handles registration, transfers, and multiple registrars, with experimental support for EPP-based registries. The built-in Support Ticketing helpdesk includes email notifications, automatic ticket closure, and access for clients and guests. Extensible Architecture allows installation of themes, modules, payment gateways, server managers, and domain registrars from an extension directory. Security features include IP blocking, reCAPTCHA, spam protection, CSRF prevention, and activity logging.

The software is self-hosted and licensed under AGPL 3.0, with the code available to audit, contribute to, or fork. It is aimed at hosting providers and operators who want to run billing and client management on their own infrastructure. The pages indicate a free download and a demo, without stating paid editions or seat-based plans.