---
title: "Enable Subscription via Inbound SMS"
slug: "subscribe-with-inbound-sms"
updated: 2025-07-25T15:20:46Z
published: 2025-07-25T15:20:46Z
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mapp.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Enable Subscription via Inbound SMS

## Goal

Allow new contacts to subscribe to a Mapp Engage group by sending an SMS containing their mobile number or email address.

---

## Prerequisites

- SMS messaging must be enabled in your Mapp Engage account.
- Coordinate with your Account Manager to:
  - Register codes and keywords for SMS
  - Obtain an inbound mobile ID
- Create a dedicated group for SMS subscriptions (subscribe and unsubscribe require separate groups).
- Enable relevant system messages for SMS:
  - `SysMsgWelcomeToGroupPasswd`
  - `SysMsgMobileEmailSubscribeSuccess` (optional)

---

## Procedure

#### 1. Define the Group’s SMS Settings

1. Navigate to *Audience > Group Management > Groups*.
2. In the *Actions* column, click the edit icon.
3. Go to the **Reply Handling** tab.
4. Expand the *SMS* section.
5. From the *Replies* drop-down, select one of the following:
  - **Treat as Mobile Subscribe Request** – adds the sender’s mobile number
  - **Treat as Email Subscribe Request** – adds the email from the SMS body
6. Save the settings.

#### 2. Format the Inbound SMS Message

Contacts can subscribe using a mobile number (from the sender) or an email address (included in the SMS body). The required SMS format depends on the type of number you’re using:

| Channel Type | Destination Number (Example) | Required SMS Body Format |
| --- | --- | --- |
| **Shared Short Code** | `12345` | `<inbound ID> <email>`Example: `NEWS joe@email.com` |
| **Dedicated Short Code** | `88888` | `<email>`Example: `joe@email.com` |
| **Dedicated Long Number** | `441234567890` | `<email>`Example: `joe@email.com` |

> [!NOTE]
> Mapp Engage uses the mobile number from the sender and/or parses the email address in the message body.

> [!NOTE]
> Note: If the contact already exists in Mapp Engage, they must have **Permissions 208 and 212** to update their address or profile information.

#### 3. Configure System Message Behavior

- If using *Treat as Mobile Subscribe Request*:
  - Sends `SysMsgWelcomeToGroupPasswd` via SMS.
- If using *Treat as Email Subscribe Request,* and you choose to store both mobile and email:
  - Also sends `SysMsgMobileEmailSubscribeSuccess` via SMS.
  - This message can be suppressed if needed.

---

### Limitations

- Each SMS group supports only one reply handling method. You cannot handle subscriptions and unsubscriptions in the same group.
- The automation event *Message Reply Received (C)* does not trigger for unknown mobile numbers, so it cannot be used for SMS-based opt-ins.

---

### Best Practices

- Use separate SMS groups for subscribing and unsubscribing flows.
- Include clear keyword instructions in your outbound SMS when using shared short codes.
- Suppress redundant system messages to prevent duplicate notifications.