# Link a budget to a custom field

Assigns a custom field to a budget. The budget must belong to the same business. Only permitted when the custom field's `budget_setting` is `SOME`.

Endpoint: POST /v1/businesses/{client_id}/custom-fields/{custom_field_id}/budgets
Version: v1
Security: BearerAuth

## Path parameters:

  - `client_id` (integer, required)
    The ID of the business.

  - `custom_field_id` (string, required)
    The ID of the custom field.

## Request fields (application/json):

  - `budget` (string, required)
    The ID of the budget to link to this custom field.
    Example: 3fa85f64-5717-4562-b3fc-2c963f66afa6

## Response 201 fields (application/json):

  - `id` (string)
    The unique identifier of the linked budget.
    Example: 3fa85f64-5717-4562-b3fc-2c963f66afa6

  - `name` (string)
    The name of the linked budget.
    Example: Marketing Q1