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Add Subscription Item


The AddSubscriptionItem API endpoint is used to add a subscription itemA subscription item is component of a subscription with its own set of attributes including price, description and feature set. to an existing subscription.

This function also supports the following:

  • A preview capability that can be used to calculate and provide the pro-rated billing amount for adding the item to the subscription. This is accomplished using the AlignmentSettings parameter.
  • The optional ability to set a price for the item that differs from what has been set up in the Commerce Assistance for the associated product. If no price is specified in the function call, then this function uses the Commerce Assistant product price.


  • Changes made by this function, including the price and/or quantity, apply to all future billing events, unless changed subsequently.
  • Use of the CustomerPrice parameter in the API response is optional. Before doing so, see Getting Started with Subscriptions > Understanding Customer Price.
  • Use of the SubscriptionAlignmentSettings parameter in the API response is required. Before doing so, see Getting Started with Subscriptions > Alignment Settings.
  • If a client adds a subscription item, a history of revisions is created automatically.
  • When a subscription item is added, the new item must have the same billing interval as the underlying subscription.

Required Parameter Settings by Use Case

Certain parameters for use cases that use this function require specific values. Set the values for the parameters as shown in the tables below.