---
title: "Message Creation: Content (SMS)"
slug: "compose-sms"
description: "Reference for the Content step of an SMS in Mapp Engage: message text, personalization, variables, link shortening, tags, encoding, and character limits."
status: "update"
updated: 2026-11-06T11:47:51Z
published: 2026-11-06T11:47:51Z
canonical: "docs.mapp.com/compose-sms"
---

> ## 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.

# Message Creation: Content (SMS)

## Overview

**What can I do in this window?**

- Create an SMS message.
- Add personalizations and Mapp Engage Variables to an SMS message.
- Add a link to an SMS Message, shorten the link, and add parameters.
- Select the SMS encoding. The encoding determines the character limit.

---

## Navigation Path​

During message creation, follow the message creation process until you reach **Content**.

![](https://cdn.document360.io/554b9b98-6720-4d8b-9919-c7b203d72648/Images/Documentation/image-A6KBSO1U.png)

---

## Content Tools​

| Tool | Description |
| --- | --- |
| **​Personalization​** | Inserts placeholders for individual user data, like names. Also supports rule-based variations for segments. Example: `<%user.FirstName%>` inserts the recipient's first name. |
| **​Mapp Engage Variables​** | Inserts static variables that render the same content for all recipients. Example: `<%CurrentDate%>` inserts the same date for all recipients during sendout. |
| **​Upload Message​** | Imports SMS content from an external file. You can also specify the character encoding here. |
| **​Shorten Links​** | Converts long URLs into shorter links to conserve character space. Parameters can be added to these URLs. |

---

## Message Information

| Setting | Description |
| --- | --- |
| **Message Name** | Required field that defines how the message is labeled within the system. |
| **External Message ID** | Adds a custom ID to outbound links for tracking in external systems. The External Message ID is helpful for tracking across analytics or eCommerce platforms. |
| **Tags** | Internal keywords to help categorize or search for the message. Each space starts a new tag. Commas are not allowed. |
| **SMS** | Your SMS message text goes here. |
| **​Characters​** | Shows the current number of characters in the message and the total allowed. > [!NOTE] > **Note**: Personalized messages may exceed character estimates due to variable replacement during sendout. |
| **​SMS Messages ​** | Indicates how many concatenated SMS parts will be sent based on the length. > [!NOTE] > **Note**: > > Message concatenation allows longer messages to appear as one SMS on most devices, but carrier support may vary. > > Charges apply for each SMS part, even if delivered as a single combined message. |
| **​Remaining​** | Displays the number of characters that are available before a new SMS message is required for sendout. |

---

## Actions​

| Setting | Description |
| --- | --- |
| **​Save as Draft​** | Saves your current message to resume editing later. |
| **​Preview​** | Opens a preview view to test and review the personalized message. |
| **​Prepare Sendout​** | Moves to the next configuration step, where sendout details are set. |

---

## Advanced Options​

| Setting | Description |
| --- | --- |
| **​SMS Encoding​** | Defines the encoding format used, which affects the character set and limit. |

---

### Character Limits

| Bit Size | Encoding | Single Message Maximum |
| --- | --- | --- |
| GSM 7-bit | ISO 8859-1 or ISO 8859-15 | 160 characters |
| 16-bit | UTF-8 | 70 characters |

## Related

- [Message Creation: Type (SMS)](/sms-message-creation-1-type.md)
- [Message Creation: Preview (SMS)](/sms-message-preview-window.md)
- [SMS Format and Encoding](/sms-format-and-encoding.md)
- [Add Links to SMS](/add-links-to-sms.md)
- [Message Creation: Configuration (SMS)](/prepare-sms-sendout.md)