Kill Bill

Kill Bill is a subscription billing and payments platform aimed at businesses that need to run recurring billing logic (subscriptions, trials, promotions, upgrades/downgrades, usage-based add-ons) without depending on the uptime, processing speed or pricing of a third-party billing SaaS. It's highly modularized rather than an all-in-one monolith, so teams can disable pieces they don't need or swap in an existing system for a specific part of the flow.

Out of the box it provides real-time analytics and financial reporting, and a plugin architecture for integrating specific payment processors and other systems. It can run on-premises or in the cloud, and keeping billing/customer data in your own infrastructure avoids the vendor lock-in that comes with a fully hosted billing SaaS.

Kill Bill is a fit for businesses running non-trivial subscription or usage-based billing who want the flexibility of an in-house system and are prepared to operate it themselves, rather than teams that just need simple one-off payments.