billing

Invoice Ninja is a powerful open-source invoicing, payment, and time-tracking platform that helps businesses manage billing, quotes, projects and expenses with extensive customization options.

Lago is an open-source metering and usage-based billing platform that helps businesses manage complex pricing models, subscriptions, and payments with extensive customization options.

Kill Bill is an open-source subscription billing and payment platform that helps businesses manage complex billing scenarios, subscriptions, and payments with extensive customization options.

InvoicePlane is a self-hosted open source application for managing invoices, clients and payments, offering comprehensive billing and client management features for small businesses.

InvoiceShelf is an open-source invoicing and expense tracking platform that helps businesses create professional invoices, manage expenses, and track payments with comprehensive features.

FOSSBilling is a free open-source billing and client management solution designed for web hosting businesses, offering automated invoicing, payment processing, and comprehensive client management capabilities.

SolidInvoice is an open-source invoicing application designed to help small businesses and freelancers manage billing operations with features like client management, quotes, invoices, and online payments.