# Pre-Authentication / Pre-Authorization
source: https://developer.mastercard.com/identity-insights-for-transactions/documentation/use-cases/use-cases-1/index.md

## Sequence Diagram {#sequence-diagram}

The following flow shows a high-level data flow between the customer and Mastercard for obtaining insights on a transaction.
This flow will work for all End-Customer or Partner Pre-Authentication, Pre-Authorization use cases.

Diagram mermaid2

### Following are the execution steps: {#following-are-the-execution-steps}

1. Consumer enters their details into e-commerce merchant.
2. E-commerce merchants submits all available details of the transaction to their decisioning platform for a decision on how to proceed with the transaction (Internal or a third party Fraud Services Provider/Payment Services Provider/Acquirer).
3. The Decisioning Platform sends a request for transaction insights to IIT.
4. IIT enriches the data in the requests with insights from its Identity Network and utilizes this to generate risk scores for the identity.
5. IIT the scores and associated signals to the Decisioning Platform.
6. The Decisioning Platform analyses the IIT scores and signals alongside other insights it has available to it, to arrive at a decision.
7.   
   1. The Decisioning Platform instructs the Merchant to allow the user to complete the transaction without any additional friction due to an extremely low risk of fraud.
   2. The Decisioning Platform instructs the Merchant that the User will need to perform an identity step-up (3DS Challenge, Biometric authentication, etc.) in order to complete the transaction due to the potential risk of fraud.
   3. The Decisioning Platform instructs the Merchant to decline the transaction due to an extremely high risk of fraud.

Note: Refer to the [API Reference](https://developer.mastercard.com/identity-insights-for-transactions/documentation/api-reference/index.md) page for more details on each endpoint and related parameters. Refer to the [Codes and Formats](https://developer.mastercard.com/identity-insights-for-transactions/documentation/code-and-formats/index.md) page for more details on error codes.