FAQs

Everything you ever wanted to know about Kill Bill

All your questions about Kill Bill, neatly categorized and answered!

About Kill Bill

Compliance & Security

Deployment

Customization

Features

Getting Started

About Kill Bill

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    What is the Kill Bill software?

    Kill Bill is an open-source programmable platform that enables you to build custom billing solutions. That’s a mouthful, to say the least, but think of it as building blocks to implement your own billing workflows.

    Similar to the Unix philosophy of composability over monolithic design, Kill Bill provides APIs to create various pricing models, manage subscriptions, generate invoices, integrate with various payment gateways, etc. Whether you are selling access to a digital service for $10 a month or selling a multi-tier cell-phone data plan, Kill Bill provides the primitives to do it so you don’t have to start from scratch.

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    Who created Kill Bill?

    Martin Westhead, Pierre-Alexandre Meyer and Stéphane Brossier designed and developed Kill Bill in 2010 as part of an open-source project at Ning.

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    How long has Kill Bill been around?

    Since 2010, Kill Bill has been running in production in private and public companies, invoicing billions of dollars and charging millions of credit cards.

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    Can I really use Kill Bill for free?

    Yes. The Kill Bill open-source software is completely free! Just make sure you follow the Apache License, Version 2.0

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    How is Kill Bill different from other billing software?

    Contrary to any SaaS solution:

    • Kill Bill is open-source. Read more: Why open-source software?
    • Kill Bill has a pluggable architecture, allowing you to write plugins (i.e., custom code) to extend or change default behaviors.
    • Kill Bill is not a batch system by default. Instead, it uses an event-oriented architecture. Modules share and react to events. For example, whenever a new invoice is generated, the invoice module sends an invoice creation event on the message bus. The payment module reacts and triggers the actual payment. These events are available to plugins, so you can write custom logic the same way.
    • Because you host your own instances, you are in full control of your data. (See also “Do you track any usage data in Kill Bill?”)
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    Does Kill Bill work with [software name]?

    Over the years, Kill Bill has been customized (either with plugins or additional logic) to work with many different types of software (for example, customer relationship management software (CRMs) and financial accounting software). If you’re interested in exploring this option, contact our software development partner for more information. 

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    Is there a Kill Bill demo?

    We have a self-directed demo that you can access here. You can click around in Kaui, the administrative user interface for Kill Bill. If you’re interested in a high-level overview, see these two short videos on Kill Bill and Kaui.

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    Why did you name your software after a famous Quentin Tarantino movie?

    We were enamored with the idea of “killing the billing problem.” Secondly, we like the Kill Bill movie!

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    Why do you have a duck as a company mascot?

    The duck seemed appropriate because what’s a duck’s main feature? Its bill! (Get it? Billing!). 

    Kill Bill logo

    P.S. His name is Killian!

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    Are there any rules for using Kill Bill (since it's open-source)?

    All of the “rules are covered in an open-source license. Kill Bill uses the Apache Version 2.0 license. Of course, there are many details, but we’ve summarized it here: Why Open-Source?

Deployment

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    Is Kill Bill a Software-as-a-Service (SaaS)?

    Kill Bill is not SaaS. It is open-source software that you can run in your own environment, a private data center, or in the cloud (AWS, Azure, etc.). 

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    Can you run Kill Bill in the cloud?

    Kill Bill has been successfully deployed in private data centers as well as in AWS, Heroku, OpenShift, Azure, etc. Our AWS deployments are offered here

Features

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    Does Kill Bill support recurring billing / usage billing / one-time billing? 

    Kill Bill supports recurring billing, usage billing, and one-time transactions. (See our Usage documentation to understand the various types of usage Kill Bill supports.)

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    How does Kill Bill handle payments?

    Kill Bill is not a payment gateway. Instead, when a payment is triggered in Kill Bill, it connects to a payment gateway, which in turn handles the payment details and processing. (For more information on payments, see our Payment Guide.)

    Connection to a payment gateway is achieved through plugins. We have some open-source payment plugins, but depending on your payment gateway, you may need to write your own plugin.

    Need help developing a Kill Bill plugin? If your organization or development team needs help creating a plugin, we can recommend partners that have created them before for Kill Bill users. Check out one of our partners here.

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    What payment gateways can I use with Kill Bill?

    Kill Bill is a generic platform to build billing and payment infrastructures. As such, it is agnostic of payment gateways.

    Kill Bill communicates to payment gateways via plugins. Thus, there are virtually no restrictions on what payment gateway you can use. See our Payment Guide for more information.

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    What types of payment methods does Kill Bill support?

    Kill Bill supports all the credit and debit cards your payment gateway supports. If your payment gateway supports ACH, then you can use Kill Bill to accept ACH, too!

    Additionally, with Kill Bill, you can track external payments (such as checks, cash, and even Boleto Bancário). When you receive the money, simply let Kill Bill know about it (either via Kaui, our administrative UI or our APIs).

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    How does Kill Bill support international billing?

    We designed the core of the billing platform to be internationalized. The catalog module has support for all currencies, including crypto-currencies (e.g. Bitcoin). The invoice module will understand these various currencies and respect localization rules. (For example, it will correctly round US dollars to two decimal places but Japanese Yen amounts will have no decimal portion.)

    Accounts can have a designated locale (for example, $1,234.99 will be displayed as 1.234,99 $ for accounts with the French Canada locale) and a time zone (to generate invoices in their time zone instead of the merchant’s).

    From a payment perspective, Kill Bill supports payment gateways via plugins. If your international gateway isn’t supported yet, you can simply write a plugin for it. 

    Note: If your organization or development team needs help writing a plugin, we can recommend partners that have created them before for Kill Bill users. Check out one of our partners here.

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    Does Kill Bill include catalog functionality?

    Kill Bill includes an XML catalog that supports these features (and more): 

    • Real-time catalog with subscription plans and one-off products
    • Product tiers
    • Pricing lists
    • Different subscription types (main subscription, add-on subscriptions, etc.)

    For more catalog information, see the Catalog section of our documentation. 

    If you have a very large catalog (e.g., thousands of products) and/or if it is highly dynamic, maintaining the catalog as an XML file may not be practical. Instead, you can use the CatalogPluginApi to write a plugin that would provide an alternative catalog implementation (such as integrating with your existing catalog system). See the documentation.

    Here are Java and Ruby examples.

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    Does Kill Bill support coupons and/or discounts?

    There are several ways to handle coupons and discounts:

    • The simplest option is for your catalog to include discount plans (plans can additionally include discount phases)
    • An alternative is to use the PhasePriceOverride element when creating a subscription
    • Finally, to implement a fully fledged coupon functionality, use the EntitlementPluginApi to write your custom plugin (here is an example)

    For more details, check this blog post.

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    Can Kill Bill send my customers email notifications about payments that are due?

    The email notifications plugin lets you send emails to your customers regarding upcoming invoices, payment successes and failures, subscription cancellations, etc.

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    Can I use Kill Bill to accept cryptocurrency payments from my customers?

    You can certainly do this; you’ll need to write a plugin to communicate with a payment gateway that supports different cryptocurrency coins (e.g., Bitcoin, Ethereum). 

    Note: If your organization or development team needs help writing a plugin, we can recommend partners that have created them before for Kill Bill users. Check out one of our partners here.

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    Where can I see a full list of Kill Bill features?

    Visit the Features page on our website. 

Compliance & Security

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    Is Kill Bill PCI compliant?

    Even if Kill Bill is used in PCI compliant companies today, it is your responsibility to get certified. Depending on how you plan to use Kill Bill, you can outsource most of the PCI complexity to your payment gateway by not storing credit card information. Check the PCI DSS website for more information.

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    Is Kill Bill GDPR compliant?

    By default, Kill Bill avoids storing any PII information. However, it is your responsibility to ensure that you remain GDPR compliant. 

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    Does Kill Bill support taxes?

    Kill Bill does not support taxes. Instead, we partner with Avalara to outsource tax compliance. Our AvaTax connector provides real-time and on-demand calculations to prevent overcharging or undercharging tax. 

    A free sandbox is available at Avalara, or you can contact us for an introduction. You can download the plugin here.

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    How can I secure my Kill Bill installation?

    Here are some general tips on securing your Kill Bill installation:

    • Install Kill Bill behind a firewall (it should not be exposed on the public internet).
    • Change the default username/password (admin/password) in your live environment.
    • Don’t store sensitive data in Kill Bill. While most plugins have support for directly saving card or bank account numbers for instance, this should only be used for testing purposes or if you use a proxy tokenizer: if you don’t, use a third-party vault.
    • Encrypt username and passwords in configuration files.
    • Use SSL for all communication with your eCommerce application as well as with the payment providers.
    • Subscribe to our Community mailing list to receive security advisories.
    • Never store security codes (CCV, CVV, etc.) in your live environment.

    It is eventually your responsibility to make sure your Kill Bill installation is secure and compliant.

Customization

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    Can I customize Kill Bill?

    Yes—there are various ways to customize Kill Bill: 

    • System properties—These let you configure the core platform. Also, most internal modules have a second, more advanced, layer of configuration, usually through XML files. These let you configure the dunning (overdue) policy, the various plans and billing policies, etc. 
    • Plugins—If you need more advanced (billing or non-billing) logic, Kill Bill has a plugin capability. You can write custom code to extend or even override Kill Bill’s default behaviors. We can recommend development partners to help you do that, if necessary.
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    Can I contribute to Kill Bill?

    We’d love to talk to you about this. Please get in touch with us. 

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    Can you develop customized Kill Bill logic or plugins for us?

    The Kill Bill team does not develop customized logic or plugins. However, we have a partner who does that. In fact, they have successfully delivered many Kill Bill projects in the past for our clients, and they are very reasonably priced. You can find out more here

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    Where is the code?

    All of our code is hosted on Github, in the killbill organization. The core of the Kill Bill platform can be found here.

Getting Started

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    Where is the documentation?

    Our documentation lives here: https://docs.killbill.io. We have documented our API here: https://killbill.github.io/slate

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    How do I get started with Kill Bill? 

    If you want to know whether or not Kill Bill would work for your organization, we recommend that you perform a Proof of Concept (POC) against your business requirements. If you have questions about Kill Bill, please start by asking them in the Kill Bill Community (mailing list). We monitor the posts and can usually answer questions within a relatively short period of time. 

    To install Kill Bill, look over the Getting Started tutorial. If you want to review the software code, it’s available on GitHub

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    Can you help us get up and running with Kill Bill? 

    We have short-term consulting and ongoing support packages that can help. Check it out here.

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    How do I set up Kill Bill in my development environment?