# Use Cases
source: https://developer.mastercard.com/mastercard-send-person-to-person/documentation/use-cases/index.md

These example use cases demonstrate a domestic payment transfer facilitated by this API. They are based on the graphical [Send money by app to a contact](https://developer.mastercard.com/mastercard-send-experience-design-guide/documentation/design/payment-transfers/send-money-by-app-to-contact/) flow in the Mastercard Send Experience Design Guide. Note that these examples do not prescribe the design and interactions of your funds transfer service; those aspects are for you to define.

### Scenario {#scenario}

* Ali Young (the Sender) is using a mobile funds transfer app to send money to Roger Quest (the Recipient).
* Ali has already added Roger as an app contact, along with his receiving card account details.
* You (the Transaction Initiator) provide the app and use the Mastercard Send APIs to do the funds transfer.
* You are partnering with a bank, who is a Mastercard customer and holds your business account. They sponsor your Mastercard Send transaction activity and are therefore regarded as the 'Sponsor Bank' or 'Sponsor Originating Institution' for your implementation.

Some example app screens --- the numbers relate to the steps in the flow below:

![alt text](https://static.developer.mastercard.com/content/mastercard-send-person-to-person/documentation/img/mastercard-send-screens-p2p.png)

### Overall flow {#overall-flow}

Diagram mastercard-send-sequence-p2p-overview

1. In the app home screen, Ali taps **Send/Request**.

2. Ali selects Roger as the recipient, enters the amount ($20 USD) and reason, and taps **Send**.

   We recommend you check the sending and receiving accounts are valid and eligible for this transfer. You can use the [Account Information](https://developer.mastercard.com/mastercard-send-account-info/documentation/), [Account Verification](https://developer.mastercard.com/mastercard-send-avs/documentation/), and [Account Validation](https://developer.mastercard.com/account-validation/documentation/) services to do this.
3. Ali confirms the payment method (sending account) and initiates the transfer by tapping **Send** again.

   Secure the funds from Ali's sending account. You can use the [Mastercard Send Funding](https://developer.mastercard.com/mastercard-send-funding/documentation/) service to do this.
4. Use a Payment Transfer API POST call to [create a payment transfer](https://developer.mastercard.com/mastercard-send-person-to-person/documentation/use-cases/create-transfer/index.md) to deliver the funds ($20 USD) to Roger's receiving account.

5. If the payment transfer status is 'APPROVED', the app indicates success and shows the transfer details in the home screen.

6. If the status is 'UNKNOWN', possibly due to timeouts or network communication issues, wait a minute and use a Payment Transfer API GET call to [retrieve the payment transfer](https://developer.mastercard.com/mastercard-send-person-to-person/documentation/use-cases/retrieve-transfer/index.md) details, including its latest status, see [this guidance](https://developer.mastercard.com/mastercard-send-person-to-person/documentation/response-error-codes/unknown-response/index.md); the status should change to 'APPROVED' or 'DECLINED'. If the status is 'DECLINED', the codes in the GET response can indicate the reason, see [here](https://developer.mastercard.com/mastercard-send-person-to-person/documentation/response-error-codes/network-response-codes/index.md).

7. When the status changes to 'APPROVED' or 'DECLINED', the app indicates the outcome.

See the detailed flows (links above) for the API calls to create and retrieve the payment transfer.

The approved API calls result in the accounts being credited or debited. The actual funds move between the financial institutions --- from Ali's issuer to Roger's Receiving Institution --- when they go through the settlement process.

### Further details {#further-details}

* [API Reference](https://developer.mastercard.com/mastercard-send-person-to-person/documentation/api-reference/payment-transfer/index.md) provides the API specification that describes the API request and response fields.
* [Transfer Status](https://developer.mastercard.com/mastercard-send-person-to-person/documentation/response-error-codes/status/index.md) shows the possible status values.
* [Error Codes](https://developer.mastercard.com/mastercard-send-person-to-person/documentation/response-error-codes/error-codes/index.md) describes the API error responses.