> For the complete documentation index, see [llms.txt](https://developers.mobile-text-alerts.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developers.mobile-text-alerts.com/tutorials/custom-subscriber-attributes.md).

# Custom Subscriber Attributes

Subscriber data is stored with predefined subscriber attributes such as First Name, Last Name, Email, etc. You can create your own fields to store any additional types of data for your subscribers. These Custom Subscriber Attributes can help you organize subscribers to create send lists, build groups, and more.

You can add/update/delete your account's Custom Subscriber Attributes in the [platform dashboard](https://platform.mobile-text-alerts.com/subscribers/attributes) or with the [Mobile Text Alerts API Custom Fields endpoints](/api-reference/custom-fields.md).

The image below shows how custom attributes appear in the platform dashboard. See [Assign Custom Subscriber Attributes](/tutorials/manage-subscribers/assign-custom-subscriber-attributes.md#manage-custom-subscriber-attributes-in-the-dashboard) to learn more.

<figure><img src="/files/3ov4Q1vbJOyIUYWdrbKP" alt=""><figcaption></figcaption></figure>

## Manage Custom Subscriber Attributes with the API

In the Mobile Text Alerts API, all endpoints for Custom Subscriber Attributes are located under `/custom-fields`. Custom Fields is the previous name for what is now called Custom Subscriber Attributes.

**Available API actions:**

* [#create-a-new-custom-subscriber-attribute](#create-a-new-custom-subscriber-attribute "mention")
* [#list-all-custom-subscriber-attributes](#list-all-custom-subscriber-attributes "mention")
* [#update-a-custom-subscriber-attribute](#update-a-custom-subscriber-attribute "mention")
* [#delete-a-custom-subscriber-attribute](#delete-a-custom-subscriber-attribute "mention")
* [#get-a-custom-subscriber-attribute](#get-a-custom-subscriber-attribute "mention")

### Create a new Custom Subscriber Attribute

A new Custom Subscriber Attribute can be created for your account by calling the [Custom Fields](/api-reference/custom-fields.md#post-custom-fields) endpoint.

**Request Body**

<table><thead><tr><th width="142">Name</th><th width="129.5">Type</th><th>Description</th></tr></thead><tbody><tr><td><code>name</code> </td><td><code>string</code></td><td>The name of the attribute.</td></tr><tr><td><code>type</code></td><td><code>string enum</code></td><td><p>The data type of the attribute, one of the following:</p><ul><li><code>string</code> </li><li><code>number</code></li><li><code>date</code> (the date format must be specified in the <code>format</code> field)</li><li><code>boolean</code> (used for check boxes)</li><li><code>select</code> (you will need to list the options in the <code>options[]</code> field)</li><li><code>address</code></li><li><code>multi-select</code> (you will need to list the options in the <code>options[]</code> field)</li></ul></td></tr><tr><td><code>options[]</code></td><td><code>string[]</code></td><td>For <code>select</code> or <code>multi-select</code> , the list of possible <code>string</code> values are listed here.</td></tr><tr><td><code>format</code></td><td><code>string enum</code></td><td><p>Determines the format of the <code>date</code> .</p><p>One of the following:</p><p><code>Month D, YYYY</code> , <code>MM/DD/YYYY</code>, <code>DD/MM/YYYY</code></p></td></tr></tbody></table>

### List all Custom Subscriber Attributes

See all Custom Subscriber Attributes that have been created on your account by calling the [Custom Fields](/api-reference/custom-fields.md#get-custom-fields) endpoint.

{% hint style="info" %}
This endpoint returns an `id` field for each attribute. Use it as the `customFieldId` in other requests to `/custom-fields` endpoints.
{% endhint %}

**Rate Limit**

This endpoint overrides the [general rate limit](/api-basics/rate-limits.md#general-rate-limit) with an account rate limit. Requests are limited by the authenticated account instead of the IP address. This endpoint is limited to `15` requests per `15` seconds.

#### **Example Request**

```bash
curl --location 'https://api.mobile-text-alerts.com/v3/custom-fields' \
  --header 'Authorization: Bearer <APIKey>'
```

### Update a Custom Subscriber Attribute

You can make changes to existing Custom Subscriber Attributes that have been created on your account by calling the [Custom Fields](/api-reference/custom-fields.md#patch-custom-fields-customfieldid) endpoint with the identifying `{customFieldId}` of the attribute to be updated as a path parameter.

**Request Body**

<table><thead><tr><th width="142">Name</th><th width="129.5">Type</th><th>Description</th></tr></thead><tbody><tr><td><code>name</code> </td><td><code>string</code></td><td>The name of the attribute.</td></tr><tr><td><code>type</code></td><td><code>string enum</code></td><td><p>The data type of the attribute, one of the following:</p><ul><li><code>string</code> </li><li><code>number</code></li><li><code>date</code> (the date format must be specified in the <code>format</code> field)</li><li><code>boolean</code> (used for check boxes)</li><li><code>select</code> (you will need to list the options in the <code>options[]</code> field)</li><li><code>address</code></li><li><code>multi-select</code> (you will need to list the options in the <code>options[]</code> field)</li></ul></td></tr><tr><td><code>options[]</code></td><td><code>string[]</code></td><td>For <code>select</code> or <code>multi-select</code> , the list of possible <code>string</code> values are listed here.</td></tr><tr><td><code>format</code></td><td><code>string enum</code></td><td><p>Determines the format of the <code>date</code> .</p><p>One of the following:</p><p><code>Month D, YYYY</code> , <code>MM/DD/YYYY</code>, <code>DD/MM/YYYY</code></p></td></tr></tbody></table>

#### Example Request

In the below example, update `customFieldId`: `7769` with a new name.

```bash
curl -L \
  --request PATCH \
  --url 'https://api.mobile-text-alerts.com/v3/custom-fields/7769' \
  --header 'Authorization: Bearer <APIKey>' \
  --header 'Content-Type: application/json' \
  --data '{
    "name": "New Name"
  }'
```

### Delete a Custom Subscriber Attribute

Custom Subscriber Attributes can be deleted  by calling the [Custom Fields](/api-reference/custom-fields.md#delete-custom-fields-customfieldid) endpoint. This request does not require a request body. Simply include the `{customFieldId}` of the attribute to be deleted as a path parameter with your request.

#### Example Request

In the below example, deleting attribute with `id: 7769`:

```bash
curl --request DELETE --location 'https://api.mobile-text-alerts.com/v3/custom-fields/7769' \
  --header 'Authorization: Bearer <APIKey>'
```

### Get a Custom Subscriber Attribute

List data for a specific Custom Subscriber Attribute with the [Custom Fields](/api-reference/custom-fields.md#get-custom-fields-customfieldid) endpoint. Include the `{customFieldId}` of the attribute to be retrieved as a path parameter.

#### Example Request

```bash
curl --location 'https://api.mobile-text-alerts.com/v3/custom-fields/7769' \
  --header 'Authorization: Bearer <APIKey>'
```

**Example Response** (for a `date` type attribute)

{% code overflow="wrap" %}

```json
{
  "data": {
    "id": 7769,
    "accountId": 1195226,
    "name": "Birthday",
    "type": "date",
    "options": [],
    "format": "MM/DD/YYYY",
    "created": "2025-07-17T20:51:34.000Z"
  }
}
```

{% endcode %}

## Use Custom Subscriber Attributes

Once you have created Custom Subscriber Attributes on your account, you can start adding custom data to your subscribers. See [Assign Custom Subscriber Attributes](/tutorials/manage-subscribers/assign-custom-subscriber-attributes.md) to learn how to add and edit these attributes for your individual subscribers.

After you have these attributes assigned to your subscribers, you can use Custom Subscriber Attributes as a condition attribute for your [Adaptive Groups](/tutorials/manage-subscribers/group-subscribers/adaptive-groups.md).


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