# Update Flight Delay Pass Registration
source: https://developer.mastercard.com/flight-delay-pass/documentation/use-cases/update-registrations/index.md

#### Overview {#overview}

Passengers can update or modify the Flight Delay Pass registration using the registration id within the deadline specified in the propositions, which varies for different merchants. The following example demonstrates how you can utilize update flight delay pass API to modify or update the flight delay pass.

API Reference: `PUT /registrations/{id}`

### Pre-condition: {#pre-condition}

* User successfully registered flight on the Issuer/Merchant UX

Diagram update-registration

### Use Case 1: If registration id is valid {#use-case-1-if-registration-id-is-valid}

1. User updates their personal information (e.g. passenger details and additional passenger details) linked to existing flight registration. User cannot update the flight information.
2. Once User updates their details, Issuer/Merchant forwards this update registration request to flight Delay Pass API
3. Flight delay pass API will validate client ID and registration ID
4. Flight delay pass API will process the update registration request and returns and success response to the Issuer/Merchant

### Use Case 2: If registration ID is invalid {#use-case-2-if-registration-id-is-invalid}

1. User updates their personal information (e.g. passenger details and additional passenger details) linked to existing flight registration. User cannot update the flight information.
2. Once User updates their details, Issuer/Merchant forwards this update registration request to flight Delay Pass API
3. Flight delay pass API will validate client ID and registration ID
4. If this registration is not found, FDP API responds with a 404 error, indicating that the registration is not found.

You will receive an error response for an invalid request or any missing request parameter.

## Additional Information {#additional-information}

1. Look at the [API Reference](https://developer.mastercard.com/flight-delay-pass/documentation/api-reference/index.md) for information on how to implement this use case.
2. Look at the [Code and Formats](https://developer.mastercard.com/flight-delay-pass/documentation/code-and-formats/index.md) for acknowledgement responses.