> ## Documentation Index
> Fetch the complete documentation index at: https://api-docs.nowbookit.com/llms.txt
> Use this file to discover all available pages before exploring further.

# PATCH /Bookings/{bookingId}/updatepax

> Update the party size for an existing booking.

Update the party size for an existing booking.

<ParamField header="X-API-KEY" type="string" required>Your API key</ParamField>
<ParamField header="Content-Type" type="string" required>Must be `application/json`</ParamField>

<ParamField path="bookingId" type="string" required>The NowBookIt Booking ID to update</ParamField>

<ParamField body="pax" type="integer" required>Updated number of guests. Must be greater than 0.</ParamField>

<CodeGroup>
  ```shell curl theme={null}
  curl --location --request PATCH '[BASE_URL]/Bookings/{bookingId}/updatepax' \
  --header 'X-API-KEY: your_api_key_here' \
  --header 'Content-Type: application/json' \
  --data '{ "pax": 6 }'
  ```
</CodeGroup>

**Example 200 Response**

```json theme={null}
{ "bookingId": "abc-123", "bookingRef": "REF-001", "amountSpent": 50.00, "status": "Confirmed", "pax": 6 }
```

| Field         | Type    | Description                  |
| ------------- | ------- | ---------------------------- |
| `bookingId`   | string  | NowBookIt booking ID         |
| `bookingRef`  | string  | Booking reference            |
| `amountSpent` | number  | Amount spent on this booking |
| `status`      | string  | Current booking status       |
| `pax`         | integer | Updated number of guests     |

| Status | Description                               |
| ------ | ----------------------------------------- |
| `200`  | Party size updated                        |
| `400`  | `The value of Pax must be greater than 0` |
| `400`  | API key not associated with a venue       |
| `400`  | `No Venue Subscribed to your App.`        |
| `401`  | X-API-KEY missing or invalid              |
| `404`  | `bookingId: {bookingId} not found`        |
| `500`  | Internal server error                     |


## OpenAPI

````yaml PATCH /Bookings/{bookingId}/updatepax
openapi: 3.0.4
info:
  title: NowBookIt IPOS Partner API
  description: >-
    REST API for integrating your POS or external system with NowBookIt's
    reservation, sales, and gift card platform.
  version: v1
  contact:
    email: platform.integrations@nowbookit.com
servers:
  - url: https://ipos.dev.nowbookit.com
    description: Development
  - url: https://ipos.nowbookit.com
    description: Production
security:
  - ApiKeyAuth: []
paths:
  /Bookings/{bookingId}/updatepax:
    patch:
      tags:
        - Bookings
      summary: Update Booking Pax
      operationId: updateBookingPax
      parameters:
        - name: bookingId
          in: path
          required: true
          schema:
            type: string
        - name: X-API-KEY
          in: header
          description: API Key authentication header
          required: true
          schema:
            type: string
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/UpdateBookingPaxRequest'
      responses:
        '200':
          description: Update Booking Pax from POS
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/UpdateBookingResponse'
        '400':
          description: Returns 400 BadRequest when passed invalid parameters
        '404':
          description: Returns 404 Not Found when trying to find Booking from NBI.
        '500':
          description: An error occurred.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ProblemDetails'
      security:
        - ApiKeyAuth: []
components:
  schemas:
    UpdateBookingPaxRequest:
      required:
        - pax
      type: object
      properties:
        pax:
          type: integer
          description: The number of guests (pax) to update the booking to.
          format: int32
      additionalProperties: false
    UpdateBookingResponse:
      type: object
      properties:
        bookingId:
          type: string
          nullable: true
        bookingRef:
          type: string
          nullable: true
        amountSpent:
          type: number
          format: double
          nullable: true
        status:
          type: string
          nullable: true
        pax:
          type: integer
          format: int32
      additionalProperties: false
    ProblemDetails:
      type: object
      properties:
        type:
          type: string
          nullable: true
        title:
          type: string
          nullable: true
        status:
          type: integer
          format: int32
          nullable: true
        detail:
          type: string
          nullable: true
        instance:
          type: string
          nullable: true
      additionalProperties: {}
  securitySchemes:
    ApiKeyAuth:
      type: apiKey
      in: header
      name: X-API-KEY

````