# Information Exchange Service
source: https://developer.mastercard.com/account-to-account-commerce-for-dsp/documentation/use-cases/information-exchange/index.md

This section outlines the use cases for implementing the Information Exchange APIs. The User experience, functionality and design is up to you to define.  

Information exchange services (IES) is a capability that will help facilitate the exchange of information to support multiple use-cases.   

![How It Works](https://static.developer.mastercard.com/content/account-to-account-commerce-for-dsp/documentation/images/ies-how-it-works.PNG)

## Alias Resolution {#alias-resolution}

This use case allows the Sender to provide an Alias of the Receiver (email address, phone number, etc.) and fetch the Receiver details from the Creditor Service Provider.
Diagram alias-resolution

The following details the steps in the above sequence diagram:   

1. Sender who wishes to send money authenticates in the Debtor Service provider mobile app.   
2. Debtor Service provider retrieves CSPs from A2A by calling `/creditor-service-providers` endpoint.   
3. A2A returns a list of participanting CSPs to Debtor Service Provider.   
4. Debtor Service provider presents the list of Creditor Service providers supported by the A2A platform.   
5. Sender selects the Creditor Service provider and provides Receiver alias.   
6. Debtor Service provider sends the Alias Resolution request to A2A by calling `/creditor-resolutions` endpoint by providing the Receiver Alias details.   
7. A2A acknowledges the request.   
8. A2A sends the outbound Alias Resolution request to Creditor Service provider by calling `/creditor-resolutions` endpoint by providing the Receiver Alias details.   
9. Creditor Service provider acknowledges.   
10. Creditor Service provider performs due diligence and collects consent from Receiver to share their account information.   
11. Creditor Service provider responds with Receivers consent and account information if approved by calling `/creditor-resolutions/{alias_lifecycle_id}/creditors` endpoint.   
12. A2A acknowledges.   
13. A2A responds with Creditor Service provider returned information to Debtor Service provider by calling `/creditor-resolutions/{alias_lifecycle_id}/creditors` endpoint.   
14. Debtor Service provider acknowledges.   
15. Debtor Service provider uses the provided information to initiate a payment transfer.