# Cancel reservation

This workflow allows third parties to cancel an existing reservation for a specific room with specified times.

The following required parameter is used in the request.

| Parameter | Description                                           |
| --------- | ----------------------------------------------------- |
| UltimoId  | The internal Ultimo Id of a reservation for the room. |

## Technical details

Basic URL (POST):

`https://customer.ultimo.com/api/V1/Action/REST_CancelReservation`

Header data:

| ApiKey               | Description                                               |
| -------------------- | --------------------------------------------------------- |
| ApiKey               | Request an API key at (application manager or consultant) |
| ApplicationElementId | Fixed value “5d5a10ee-7b14-4dd4-8683-33822ea56f12”        |

Body (example):

```csharp
{
    "UltimoId": "00000006712"
}
```

### Normal response:

{% hint style="success" %}
Status: 200 OK
{% endhint %}

```csharp
{
    "properties": {}
}
```

### Response when the API-key is invalid:

{% hint style="danger" %}
Status: 401 Unauthorized
{% endhint %}

```csharp
{
    "message": "Missing API key",
    "code": "MissingApiKey"
}
```


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://developer.ultimo.net/api-key-templates/reservations/cancel-reservation.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.