Kill Bill Overview
Kill Bill Features: Bill, Collect and Report
Kill Bill is the open source billing and payments platform behind B2B SaaS, consumer services and B2B2C marketplaces, with usage billing, multi-tenancy and plugins, in production since 2010.
Last updated: October 2026
Trusted by companies processing billions in revenue
Short answer
What can Kill Bill do?
Kill Bill handles the full billing cycle: a catalog of plans and prices, subscriptions and usage, invoices generated as events happen, payments through gateway plugins, retries and dunning, tax through tax plugins, and reporting. It runs many tenants in one deployment, records every change in audit logs, and can be extended with plugins. All of this is open source and free. Aviate, the enterprise offering of Kill Bill, adds enterprise features and Level 3 support.
Process Billing Events in Real Time
Kill Bill is event driven, not a batch system. When a subscription starts or changes, Kill Bill generates the invoice and triggers the payment right away, so your billing data stays current.
Extend Anything Through Plugins
Connect payment gateways and tax engines, integrate other vendors, or add your own business logic through plugins, without changing the core code.
Stay Audit-Ready
Every change is recorded in the audit log. See the history of any object in Kaui: who changed it, when, and why.
Run Several Businesses from One Deployment
Run several stores, brands, regions or test environments as tenants of one deployment, with the data of each tenant kept separate.
Adapt the Data Model to Your Business
Add tags and custom fields to any object: tag a customer as VIP, flag an account for review, or store business-specific data.
Feature List
Every Kill Bill Feature at a Glance
Kill Bill features are open source and free. Aviate features come with the enterprise offering.
| Feature | What it does | Edition |
|---|---|---|
| Catalog and pricing | Plans, phases such as free trials, add-ons, price lists and several currencies, in an XML catalog. Aviate adds a catalog editor. Catalog | Kill BillAviate |
| Subscriptions | Create, change, pause, resume and cancel subscriptions, with change policies and proration. SaaS billing | Kill Bill |
| Usage billing | Price usage in tiers or blocks and bill it in arrears. Aviate Metering ingests usage events. Usage metering | Kill BillAviate |
| Invoicing | Invoices generated as events happen and on billing dates, with credits, adjustments, draft invoices and dry runs. | Kill Bill |
| Payments | One payment API across gateways through plugins, with refunds and chargebacks. Payment platform | Kill Bill |
| Retries and dunning | Retry schedules for failed payments, then overdue states that block changes or pause the service. | Kill Bill |
| Tax | Tax plugins for Avalara AvaTax, Vertex and Kintsugi. Aviate Tax adds rates per country and per product. Tax compliance | Kill BillAviate |
| Multi-tenancy | Many tenants in one deployment, each with its own catalog, configuration and API keys. Enterprise operations | Kill Bill |
| Audit and history | Audit logs with who changed what, when, and why, readable in Kaui and through the API. Kaui | Kill Bill |
| Tags and custom fields | Attach tags and key-value fields to accounts, invoices, payments and other objects. | Kill Bill |
| Plugins and events | Plugins for gateways, tax and custom logic, and push notifications to your systems. Plugins | Kill Bill |
| Reporting | Reports from the analytics plugin, viewable in Kaui. | Kill Bill |
| Coupons and prepaid credits | Aviate Coupons and Aviate Wallet for coupons, top-ups and prepaid credits. Wallet and credits | Aviate |
| Health monitoring | Aviate Health: node metrics, stuck bus and notification entries, diagnostic reports. | Aviate |
FAQs
Kill Bill Features FAQ
What features does Kill Bill include?
Kill Bill includes a catalog, subscriptions, usage billing, invoicing, payments through gateway plugins, retries and dunning, tax through tax plugins, multi-tenancy, audit logs, tags and custom fields, plugins, push notifications and reporting through the analytics plugin. All of it is open source under the Apache 2.0 license.
Is Kill Bill real time or batch?
Kill Bill is event driven. When a subscription starts or changes, it generates the invoice and triggers the payment right away. Recurring invoices are generated on each billing date.
Does Kill Bill support usage-based billing?
Yes. You price usage in tiers or blocks in the catalog, record usage through the API, and Kill Bill bills it in arrears. Aviate Metering adds ingestion of usage events.
Can one Kill Bill deployment run several businesses?
Yes. Each business, brand, region or test environment can be a tenant, with its own catalog, configuration and API keys, and its data kept separate.
How does Kill Bill keep an audit trail?
Every change is recorded in the audit log with the user, the date, a reason code and a comment. You can read the history of an object in Kaui or through the API.
Which features need Aviate?
The Kill Bill features are free and open source. Aviate, the enterprise offering of Kill Bill, adds a catalog editor, Aviate Coupons, Aviate Wallet, Aviate Metering, Aviate Tax and Aviate Health, plus Level 3 support, for a fixed annual fee.
Does Kill Bill include reporting?
Yes, through the open source analytics plugin. It provides ready-made reports and lets you create your own, and you view them in Kaui.
Ready to Transform Your Billing?
Explore the enterprise sandbox, talk to our team, or connect with the Kill Bill community.
Support
Work directly with the Kill Bill core team
Kill Bill Community
For technical questions, start by asking the Community
Documentation
Organized product documentation library and API Reference
Customization
Work with experts for Kill Bill customization