Overview

Kill Bill is an open-source billing platform for businesses that need programmable subscription, pricing and payment workflows. It is best suited to technical teams that want control over billing logic and deployment; organizations seeking a managed service without operational work should look elsewhere.

Founded in 2010, it provides APIs for pricing models, subscriptions, invoices and payment integrations, with Kaui as a web-based interface for staff. Its flexibility is useful when billing needs call for customization, but self-hosting makes the customer responsible for running and upgrading the system.

Key features

Subscription and payment workflows

Kill Bill supports recurring and usage-based billing, multi-currency billing, proration controls, dunning automation and tax automation. Those capabilities cover several recurring-revenue tasks in one platform, making it relevant to businesses whose pricing or payment workflows need more than a fixed subscription model.

Payment plugins connect to gateways, issuing banks and fraud tools. Named integrations include Stripe, Adyen, PayPal, Braintree, GoCardless, Coinbase, Avalara and Vertex. The plugin approach gives teams options across payments and tax, but building and operating a deployment remains a technical responsibility.

Administration and security

Kaui gives staff a web back office for configuring price books and managing subscriptions and payments. The platform describes encryption at rest and in transit, TLS communications, AES-256 encryption for stored data, audit logs, role-based access controls and multi-tenant isolation. Its technical controls are intended to help enterprises meet SOC 2 and PCI-DSS requirements, rather than serving as a claim that compliance is automatic.

Pricing

Kill Bill uses a freemium model and offers a free plan and free trial. The self-hosted open-source option has no published price and includes the open-source core with control over infrastructure and data. It is the fit for teams able to manage deployment and upgrades; community support is included, while paid support tiers are purchased separately.

The Hosted Platform (ChaChing) has custom pricing under a separate commercial model. It is fully managed and uses the same Kill Bill APIs and data model, making it the option for teams that want managed operation rather than running the stack themselves.

AWS Marketplace is priced at ~$40/mo, plus AWS infrastructure costs. It runs in the customer’s AWS account, so the customer still operates the stack. That price is a starting point, not the full infrastructure bill, and this option does not remove the maintenance work of self-hosting.

Platforms

Kill Bill supports API, Linux, macOS, Windows, web and self-hosted use. The maker provides Docker and Tomcat installation options and says it can run on Windows, Mac or Linux computers, or on a Linux cloud server. These choices suit teams selecting their own environment, but do not change the operating and upgrade responsibilities of customer-managed deployments.

Who it's for

Online businesses, startups and growth-stage companies can consider Kill Bill when they need configurable subscription or usage billing and have technical capacity to implement and operate it. It is a less natural fit for teams that want billing infrastructure managed for them unless they choose the separately priced hosted platform.

Pros and cons

Pros

Supports both subscription and usage-based billing, alongside proration, dunning, tax and multi-currency capabilities, giving teams several recurring-billing tools in one platform.
Plugins connect to a broad mix of payment and tax providers, including Stripe, Adyen, PayPal, Avalara and Vertex.
Self-hosting gives customers control over their infrastructure and data, with deployment options for common operating systems.

Cons

Self-hosted customers must operate and upgrade the system, which adds ongoing work for technical teams.
Community support comes with the open-source option; paid support for customer-managed deployments costs extra.
AWS Marketplace pricing excludes AWS infrastructure costs, and customers still operate the stack.

Alternatives

For a free invoicing option and usage billing billed per successful transaction, consider Airwallex Billing. Churnkey is another option. OpenBRM may suit readers comparing free billing software for web and desktop platforms.

Pabbly Subscriptions offers a free plan capped at 50 customers, with revenue limited and team members and the affiliate module excluded; it may suit a small operation within those limits. UniBee has a free, self-hosted open-source plan with manual setup and community support, a similar route for teams prepared to manage deployment.

Flexprice offers a free plan with a 100k-events-per-month cap and up to $100K in cumulative billing revenue, plus subscription, usage-based and hybrid pricing. Lago offers a free, self-hosted open-source plan under AGPLv3, while its premium pricing is custom.

Lemon Squeezy has no monthly ecommerce fee but charges 5% + $0.50 per transaction, which may suit businesses preferring transaction-based ecommerce pricing.

Verdict

Choose Kill Bill if your team needs programmable subscription and usage billing, values control over its infrastructure and data, and can handle the operational work of self-hosting. Its broad billing capabilities and integration options are the main draw. Look elsewhere if you need a customer-managed deployment with included paid support, or want AWS Marketplace use without separate infrastructure costs and stack operations.

	Kill Bill	Shift4 Payments
Free plan	Yes	No
Free trial	Yes	No
Paid from	Free	—
Open source	No	No
Platforms	api, Linux, macOS, self-hosted, Web, Windows	Android, api, Web
Free plan	Yes	No
Paid from	40 /mo	29.99 /mo
Multi-currency support	Yes	—

Kill Bill vs Shift4 Payments

Kill Bill

Shift4 Payments