> ## Documentation Index
> Fetch the complete documentation index at: https://docs.birdeye.com/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.


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