> ## Documentation Index
> Fetch the complete documentation index at: https://docs.slm.m1amdocs.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Enable Existing Customers to Purchase a Single Use Product

You can enable existing customers to purchase a single-use product using their on-file payment method. To support this functionality, you must use the Subscribe APIs.

* **Use Case Number:** 2-4-15
* \*\*Completed By:\*\*Software Developer
* **Estimated Completion Time:** \<3 days

## Basic Scenario

A customer logs in to your self-care portal and chooses to purchase a single use product. For example, an existing subscriber with a video streaming subscription wants to purchase a movie.

Single use products allow customers to purchase a service that does not recur.

## Design Approach

The existing customer logs into your self-care application and selects the single use product for purchase. The self-care application uses the attributes of the single use product in conjunction with the end user account and payment information to call the transactions endpoint to create a one-time transaction for this purchase.

If entitlements are in scope, upon successful completion of the one-time transaction, grant the appropriate entitlements (from the single-use product attributes) to the customer using the accounts endpoint.

<img src="https://mintcdn.com/amdocs-slm/ifa3y22T11JlqvtT/portal/vindiciaSubscribeAndNewRetain/subscribeUseCases/images/SubE_4_015_Existing_customer_purchases_single_use.png?fit=max&auto=format&n=ifa3y22T11JlqvtT&q=85&s=0856f566eafb88f92fde40670a75b9fd" alt="" width="615" height="512" data-path="portal/vindiciaSubscribeAndNewRetain/subscribeUseCases/images/SubE_4_015_Existing_customer_purchases_single_use.png" />

## Video example

* **[Create the Single Use Transaction for Existing Customers Using Subscribe APIs](../topics/2415_r_customerPurchasesSingleUse#)**

**Parent topic:**[Single Use Products](../topics/r_singleUseProducts)

## Create the Single Use Transaction for Existing Customers Using Subscribe APIs

* Create the single use product in Subscribe using either the portal or API (see [Configure Single Use Products Using the Subscribe Portal](2105_r_configureSingleUsePortal#)).
* Refresh your product catalog cache using the products endpoint (see [Set Up Local Data Cache of Products to Display on Your Online Storefront](2201_r_displayProductOffers#)).

To create the one-time Transaction for existing customers:

1. Use the transactions endpoint to create the one-time transaction.

2. (optional) Use the accounts endpoint to create the entitlements grant for the single use content.

   **Sample Code**

   [2-4-15 Sample Code](https://github.com/Vindicia/CashBoxRESTCodeSamples/tree/master/SubE-4-015)

* A one-time Transaction is generated if applicable, including any applicable taxation, and charged to the customer's on-file payment information.
* The Account has been granted appropriate entitlements, if applicable.

**Parent topic:**[Enable Existing Customers to Purchase a Single Use Product](../topics/2415_r_customerPurchasesSingleUse#)


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