The Foundation of a Flexible Subscription Product Catalog

by | Jul 14, 2021 | Billing Systems, Catalog

Product catalogs on a tablet

At its most basic, the product catalog is a list of products (or services) with prices. However, it’s crucial for today’s SaaS and ecommerce organizations to have a flexible subscription product catalog. This requires many more components than just product name and price.

This is Part 1 in a three-part series about the subscription product catalog. We’re going to be describing a product catalog’s components from the most basic to the more complex. (To skip ahead, read Part 2 and Part 3.)

We’ll be referring to the Kill Bill catalog throughout. However, this is also helpful for those designing the architecture of their own subscription product catalog or evaluating existing ones.

Let’s start with the basics: 

  • Products
  • Plans
  • Plan phases
  • Price lists


The product is what the customer is buying. Here are a few product examples from a subscription product catalog: 

Business What the customer is buying
SaaS Access to software (for example, Dropbox) or a service (for example, like Netflix)
Ecommerce subscription box  Regular delivery of a curated box of items
  • Mobile phone 
  • Data plan (access to cell data towers for phone communication)


For additional configurability, you can assign a category to a product: 

  • Add-on
  • Base
  • Standalone

Add-on products let your business specify the inclusion and availability of Add-on products with associated Base products. For example, if a customer cancels a plan that consists of a Base product plus an Add-on product, both products get canceled. In effect, you cannot have a subscription to an Add-on product without it being associated with an existing Base subscription.


While it seems like a plan IS the product, in the Kill Bill terminology for a subscription product catalog, the plan serves as an agreement between the customer and the business, defining the details about customers’ access to the product. 

The product is the WHAT. 

The plan is the HOW (and HOW MUCH).

Note: While a plan is associated with only one product, a product can be associated with more than one plan. 

For maximum flexibility, a plan is composed of one or more phases. So it’s at the plan phase level that you define those nitty-gritty details mentioned (price, billing frequency, etc.). 

Plan Phases

A plan phase can be categorized as one of the following: 

  • Trial
  • Discount
  • Fixed term
  • Evergreen

Each plan phase includes the following details: 

  • Duration—How long the phase lasts in days, months, years (could be unlimited)
  • Billing period—How frequently the customer is billed (weekly, biweekly,  monthly, annually, etc.)
  • Fixed price—Optional price charged at the beginning of the phase (in addition to the recurring price).
  • Recurring price—Amount that needs to be paid every billing period 

Example 1: 

Phase 1: 14-day trial period
Phase 2: evergreen phase 

Example 2: 

Phase 1: trial period (30 days)
Phase 2: discount period
Phase 3: evergreen phase

Price Lists

A price list in Kill Bill is a way to specify a set of plans that, as a group, define special pricing for a set of customers. In addition to a default price list, you could, for example, also have a VIP price list or an affiliate price list. Whereas the VIP price list includes plans that are 20% off the default price list, the affiliate price list includes plans that are just 10% off.

What’s great about price lists is that you can set them up so that when a customer wants to upgrade or downgrade their plan, Kill Bill knows which price list to use. You might allow that customer to remain with the same price list, or you might specify they must return to the default price list.

You can fulfill these use cases by using price lists with catalog rules, which we’ll cover in Part 2. (And here’s Part 3!)

We hope you enjoyed this catalog overview…

As always, if you have any questions about designing or working with subscription product catalogs, you can contact us or post it in the Kill Bill Community. Thanks for reading!

Want more info on product catalogs? Check out our documentation. And below is an older blog post on the topic; what we wrote is still relevant!

Moving Towards a Flexible Catalog

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