# Merge custom attributes

`PUT /api/contacts/{phone}/attributes`  (operationId: `setContactAttributes`, group: Contacts)

Merges the given attributes into the contact’s existing ones. Keys you leave out are kept; use Delete a custom attribute to remove one.

Part of the core API, included in the Growth and Scale plans. Any one of these scopes is enough: `contacts`.

**Parameters**

| Name | In | Type | Required | Description |
| --- | --- | --- | --- | --- |
| `phone` | path | string | yes | Contact phone number with the country code, digits only. A leading + is accepted. A 10-digit number with no country code is treated as Indian (91 is added). |

**Request body** (JSON, required)

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `attributes` | object | yes | Key and value pairs to merge in. |

Example:

```json
{
  "attributes": {
    "plan": "Business",
    "renewal": "2026-12-01"
  }
}
```

**Response 200**: The merged attributes.

Example:

```json
{
  "success": true,
  "attributes": {
    "plan": "Business",
    "renewal": "2026-12-01"
  }
}
```

**Errors specific to this call.** The common ones (401, 403, 429 and the rest) are in the [Errors guide](https://inboxwa.online/docs/api/guide/errors.md).

| Status | error | When |
| --- | --- | --- |
| 400 | `attributes object is required` | attributes is missing or not an object. |

Part of the InboxWA API reference: https://inboxwa.online/docs/api . Full reference as one document: https://inboxwa.online/docs/api.md . OpenAPI: https://inboxwa.online/openapi.json