# Use Cases
source: https://developer.mastercard.com/unified-installments/documentation/use-cases/index.md

## Use Cases {#use-cases}

Use these pages to choose the installment flow that matches your role, then map each step to the API endpoints it uses.

|                                                                                                                Use case                                                                                                                 |               Who implements it                |                                                  When it applies                                                  |                                                                                       Endpoints                                                                                        |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------|-------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| [Post Purchase](https://developer.mastercard.com/unified-installments/documentation/use-cases/mastercard-installments-payment-services/post-purchase/index.md)                                                                          | Issuer or issuer processor                     | A cardholder converts a completed card purchase into installments in the issuer app or statement.                 | `POST /consumers/pans/registrations`, `POST /consumers/pans/deregistrations`, `POST /offers`, `POST /plans`, `POST /notifications` (outbound)                                          |
| [During Purchase](https://developer.mastercard.com/unified-installments/documentation/use-cases/mastercard-installments-payment-services/during-purchase/index.md)                                                                      | Distribution partner, with issuer or processor | A consumer chooses an installment offer at checkout through a wallet, merchant, or payment service provider.      | `POST /consumers/pans/registrations`, `POST /consumers/pans/deregistrations`, `POST /offers`, `POST /plans`, `POST /card-offers/searches` (outbound), `POST /notifications` (outbound) |
| [Pre-approved offer delivered in lender app before purchase](https://developer.mastercard.com/unified-installments/documentation/use-cases/mastercard-installments-program-with-merchant-participation/merchant-participation/index.md) | Acquirer or Installment Program Provider (IPP) | An acquirer records merchant participation so a consumer can pay with an installment credential issued by an IPP. | `POST /merchants/participations`, `GET /merchants/participations`, `POST /merchants/mids/searches`, `POST /merchants/searches`                                                         |

For product overviews, see [Mastercard Installments Services](https://developer.mastercard.com/unified-installments/documentation/use-cases/mastercard-installments-payment-services/index.md) and [Mastercard Installments Credential](https://developer.mastercard.com/unified-installments/documentation/use-cases/mastercard-installments-program-with-merchant-participation/index.md).

## Next Steps {#next-steps}

* Set up credentials and make a first call with the [Quick Start Guide](https://developer.mastercard.com/unified-installments/documentation/quick-start-guide/index.md).
* Validate each flow with the [Testing](https://developer.mastercard.com/unified-installments/documentation/testing/index.md) scenarios.