The dynamic SMS sender feature lets you send one SMS campaign from different phone numbers, depending on who the recipient is. Instead of using one sender for everyone, the system checks a specific attribute assigned to each recipient and automatically chooses the right SMS account based on that. The selection is based on a [Brickworks](/docs/assets/brickworks) schema, where the mapping between attribute values and sender accounts is defined.

This is designed for multibrand or multilingual operations where each market or brand requires a dedicated sender number. For example, a company that operates in multiple regions can ensure that recipients in each region receive the text message from the correct regional phone number.


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If a recipient's profile attribute value does not match any record in the schema, or if the schema has been deleted, the campaign is not sent to that recipient. An [`sms.notSent`](/docs/assets/events/event-reference/sms#smsnotsent) event is generated instead.

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## Requirements
---
- At least two [SMS sender accounts](/docs/campaign/SMS/configuring-sms-gateway#create-sms-account) must be configured in the workspace.
- You must have the following user permissions:
    - [create and edit schemas](/docs/settings/identity-access-management/permissions/data-management-permissions#create-and-edit-schemas)
    - [create and edit records](/docs/settings/identity-access-management/permissions/data-management-permissions#create-and-edit-records)
    - if you plan to create versioned schemas, then you need permissions to [publish records](/docs/settings/identity-access-management/permissions/data-management-permissions#publish-records).
- The recipients of the SMS must have a profile attribute whose values correspond to the mappings defined in the Brickworks schema. You choose which attribute to use - any profile attribute can serve as the basis for sender account assignment.

## Creating a Brickworks schema with mapping
---

Before you can use the dynamic sender in a campaign, you must create a Brickworks schema that maps profile attribute values to sender accounts.

### Getting the sender account ID

In further steps, you will need the IDs of the sender accounts. To find the ID of a sender account:
1. Go to <img src="/api/docs/image/6dadd64d13e4887e32e8c519b4b2b3da1066cba4/icons/settings-icon.svg" alt="Settings icon" class="icon"> **Settings > SMS**.
2. Click the sender account you want to use.
3. Copy the ID from the URL of the page.

### Creating the schema

In this part of the process, you will create a schema with the following fields:

| Field | Type | Constraints | Description |
|---|---|---|---|
| `profile_attribute_name` | String | Required, Constant | The name of the profile attribute used for matching. The value must be identical across all records in the schema. |
| `attribute_value` | String | Required, Unique | The value of the profile attribute that corresponds to this sender account mapping, for example, a region code such as `PL` or `EN`. |
| `sending_account` | Number (Integer) | Required | The ID of the SMS sender account to use for recipients whose attribute matches the `attribute_value`. |

1. Go to <img src="/api/docs/image/6dadd64d13e4887e32e8c519b4b2b3da1066cba4/icons/data-modeling-hub-icon.svg" alt="Data Modeling Hub icon" class="icon"> **Data Modeling Hub > Brickworks**.
2. Create a new schema. For more information on creating schemas, see:
    - [Creating a schema](/docs/assets/brickworks/quick-start/creating-a-schema)
    - [Field types](/docs/assets/brickworks/schema-field-types)
3. In the **Fields** tab, add the following fields:
    1. Add a **String** field:
        - In **API name**, enter `profile_attribute_name`
        - Select the following options for this field:
            - **Required field**
            - **Block record-level overwriting** - This setting requires you to provide a default value for this field in each record — enter the name of the profile attribute used for matching.
    2. Add a **String** field:
    - In **API name**, enter `attribute_value`
    - Select the following options for this field: **Required field** and **Unique values only**.
    3. Add a **Number** field:
    - Set the type to **Integer**.
    - In **API name**, enter `sending_account`
    - Select the **Required field** checkbox.
4. Save the schema.

<figure><img src="/api/docs/image/6dadd64d13e4887e32e8c519b4b2b3da1066cba4/docs/campaign/_gfx/schema-dynamic-sender.png" class="medium" alt="Preview of a schema for dynamic sender allocation"><figcaption>Preview of a schema for dynamic sender allocation</figcaption></figure>

### Adding records

After creating the schema, add a record for each sender account you want to map:

1. Open the schema and go to the **Records** tab.
2. For each mapping, add a record with the following values:
    - In `profile_attribute_name`, the value is already provided due to the **Block record-level overwriting** option in the field setting.
    - In `attribute_value`, enter the attribute value that identifies this group of recipients (for example, `PL`).
    - In `sending_account`, enter the ID of the sender account assigned to this group.
    <figure><img src="/api/docs/image/6dadd64d13e4887e32e8c519b4b2b3da1066cba4/docs/campaign/_gfx/dynamic-sender-record.png" class="medium" alt="An example record"><figcaption>An example record</figcaption></figure>
3. Repeat for each sender account you want to map.

To learn about limits on schemas and records, see [Limits and constraints](/docs/assets/brickworks/limits).

#### Example

In this example, three records are added to the schema:

| Records | `profile_attribute_name` | `attribute_value` | `sending_account` |
|---|---|---|---|
| record1 | `region` | `PL` | `6235` |
| record 2 | `region` | `DE` | `6236` |
| record 3 | `region` | `EN` | `6237` |

In this example, recipients with `region = PL` will receive the text message from account `6235`, recipients with `region = DE` from account `6236`, and so on.

### Selecting the schema in a campaign

Once the schema is ready, select it when creating an SMS campaign:

1. In the **Content** section of the campaign, select **Dynamic sender**.
2. In the **Schema** field, select the schema you created.

For the full SMS setup, see [Sending SMS](/docs/campaign/SMS/sending-sms).