Kill Bill Solutions

Subscription Billing, Payment Platform, and Kaui

Kaui Features

Kaui is the Kill Bill admin user interface for Kill Bill, an open-source billing and payment solution. It’s an online application for your organization’s many business objects (accounts, invoices, payments, etc.). Customer support, operations, finance teams, product managers, and developers can use Kaui to manage and configure Kill Bill.

Here’s What You Can Do with Kaui

  • Manage an account and its subscriptions, invoices, and payments
  • Manage back-office users and configure their associated roles and permissions
  • Edit subscription plans and pricing in real-time without involving developers
  • Perform customer service tasks (Examples: manage subscriptions and accounts, check balances, process refunds)
  • Advanced search functionality for any Kill Bill object
  • Audit and history screens with full history of objects and what changed over time
  • Manage custom tags
  • Display default KPIs like MRR in real-time and ability add your own metrics
  • Install/uninstall plugins as well as start, stop, and restart them

Core Features of Kill Bill

Kill Bill can fulfill the billing and payment needs of nearly any online business. Reliable and robust, it has proven itself over time with even the largest SaaS and e-commerce organizations.

Kill Bill is an event-based system
Kill Bill data is instantly available for analytics and reporting. Unlike batch-processing systems, Kill Bill creates an invoice and starts payment processing immediately after the appropriate event is triggered.

Plugins provide customized business solutions
Enhance Kill Bill with Java or Ruby plugins. For example, use plugins to connect with new payment gateways and processors. Integrate with third-party vendors.

Built-in auditing to support compliance

See a full history of objects in Kaui and who made the changes.

Kill Bill supports multi-tenancy

Run several instances of Kill Bill at once to support multiple stores, locations, or test environments.

Support for custom tags and custom fields

Use custom tags and fields to suit your business, such as tagging a customer as “VIP” for Customer Service.

Don’t forget to check out the features for Subscription Billing, Payment Platform, and Kaui.

Subscription Billing Features

Kill Bill Subscription Billing gives you all the flexibility you need to manage subscriptions and support your unique business requirements.

Subscription Management

  • Subscriptions can be created, upgraded, downgraded, paused, cancelled, resumed, renewed, suspended, etc.
  • Flexible plan management to support multiple billing scenarios and payment plans
  • Automatic transition of customers from one phase of a plan to the next (Example: from a 7-day trial phase to the evergreen phase)

Additional logic or plugins required:

Automated subscriber communications triggered for sign-up, account pause, late payment, and other events

Catalog Flexibility

Products, Subscriptions, and Add-Ons

  • Real-time catalog supports subscription plans and one-off products
  • Product tiers
  • Variety of subscription types (main subscription, add-on subscriptions, etc.)
  • Specify add-ons only available with certain product types/levels (when the customer upgrades or downgrades, add-ons that are not available are automatically cancelled)


  • Support for one-time charges (Examples: equipment fee, set-up fee, etc.)
  • Subscription bundles to bill multiple subscription types as one


  • Catalog rules to determine system behavior when a plan is created, cancelled, or changed
  • Make catalog changes and specify how and when they apply to new and existing subscriptions
  • Automatic cancellation of plans based on business rules
  • Plan change rules to determine when to apply upgrades and downgrades


  • Multiple phases can have different price and payment terms (Example: $0 trial period followed by $2.99/month for six months, which transitions to an evergreen subscription for $5.99/month)
  • Price lists with plan change rules to give special pricing to certain customers (Example: Show a discounted price list to referral customers who visit your website via a specific link)

Additional Logic or Plugins Required

  • Gift certificates and promo codes
  • Configure, price, and quote (CPQ) for complex deal arrangements (multi-year arrangements, different contract durations, etc.)

Invoice & Billing

  • Automatic, real-time invoice creation to trigger payment
  • Automatic invoice proration from refunds, credits, upgrades, chargebacks, adjustments, downgrades, cancellations, etc.
  • Variety of billing frequencies and billing models (fixed recurring, one-time charge, usage-based, seat-based, etc.) 
  • Aggregate invoicing (bill multiple subscriptions on the same invoice)
  • Alignment renewals (same-day renewal of base subscription and add-ons)
  • Billing alignment rules (determine if a plan should be billed independently or on the account billing date)
  • Tax support on invoices

Analytics & Financial Reporting

  • Real-time key subscription metrics like MRR, churn, LTV, CAC
  • Dashboard-building tools 


  • Time zones and localization
  • Template engine to have invoices and emails in multiple languages
  • Multiple currencies

Payment Platform Features

Kill Bill interfaces with payment providers (payment gateways, issuing banks, credit card companies) via a well-defined plugin API. This makes it easy to add new payment providers if you need to communicate with providers not yet supported.

  • Real-time billing and payment
  • Support for virtually all payment flows (Examples: banks, payment gateways, hosted payment websites, offline payment methods)
  • Support for nearly any payment method (Examples: credit or debit cards, ACH, wire transfers, cryptocurrency, etc.)
  • Define actions for failed payments and overdue payments
  • Detect downtimes and route payments to alternate processors in real-time
  • Loose coupling with billing state to allow for exceptions (such as a grace period for larger accounts)
  • Additional security (3D Secure process, Apple Pay) to conform to regulations for PSD2/SCA (Payment Services Directive 2 / Strong Customer Authentication)
  • Plugins to connect with virtually any payment gateway and processor (Examples: Stripe, Adyen, PayPal, etc.)
  • Control how many payments should flow through each payment provider

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