> ## Documentation Index
> Fetch the complete documentation index at: https://birdeye-0229a3ce-cgupta-healthcare.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Update Custom Field

> Update an existing custom field's configuration.

```
update_custom_field
```

## Description

Updates an existing custom field's configuration. Use it to change the default value or description, add or change dropdown options, hide the field, or toggle whether it is filterable.

<Warning>
  This is a **write tool** — it overwrites the field's configuration. Confirm the field and the new values with the user before calling. When changing dropdown options, pass the **complete** desired list — existing options are not merged, so omitting one removes it.
</Warning>

## Parameters

| Parameter          | Type          | Required | Default | Description                                                                                                               |
| ------------------ | ------------- | -------- | ------- | ------------------------------------------------------------------------------------------------------------------------- |
| `fieldId`          | integer       | Yes      | —       | ID of the custom field to update. Resolve via [`get_custom_fields_list`](/mcp/tools/custom-fields/get-custom-fields-list) |
| `businessNumber`   | string        | Yes      | —       | Business number that owns the field                                                                                       |
| `defaultValue`     | string        | No       | —       | New default value                                                                                                         |
| `dropDownOptions`  | list\[string] | No       | —       | The **full** list of options (not merged with existing — pass every option to keep)                                       |
| `fieldDescription` | string        | No       | —       | New description                                                                                                           |
| `filterable`       | boolean       | No       | —       | Whether the field can be used as a filter                                                                                 |
| `isHidden`         | boolean       | No       | —       | Whether the field is hidden                                                                                               |

## Example Usage

```
Add "Yellow" to custom field 376's options.
```

```
Change the description on custom field 376.
```

```
Hide custom field 376.
```

## Notes

* Returns a success response when the field is updated.
* When changing dropdown options, pass the complete list — omitting an existing option removes it.
* Resolve `fieldId` via [`get_custom_fields_list`](/mcp/tools/custom-fields/get-custom-fields-list) (match the field by name) if the user refers to the field by name rather than ID.