# SMS Message Requirements and Limits

SMS messages have stricter length and data requirements than email messages. Review these limits before composing an SMS campaign so that personalization, URLs, and encoding do not create unexpected segments or delivery failures.

## Message Requirements

| Requirement | Details |
|  --- | --- |
| Sender | A Treasure AI-provisioned short code assigned to the workspace |
| Recipient phone number | A phone number in [E.164 format](https://help.twilio.com/articles/1260803420489), such as `+12125551234` |
| GSM-7 message | Up to 160 characters per segment |
| Unicode message | Up to 70 characters per segment |
| Long message | Uses multiple SMS segments; review the segment count because each segment adds delivery cost |
| Personalization | Liquid variables must reference mapped audience columns |
| URL | Use an HTTPS URL for Treasure AI link shortening |


## Character Encoding and Segments

[GSM-7 messages](https://www.twilio.com/docs/glossary/what-is-gsm-7-character-encoding) support up to 160 characters per segment. A message containing characters outside the GSM-7 character set, including many emojis, can use Unicode encoding and support up to 70 characters per segment.

Engage Studio displays the segment count while you compose the message. Check the count again after adding Liquid values, UTM parameters, or links because rendered values can change the final message length.

For link-specific limits, see [Shorten Links in SMS Campaigns](/ja/products/marketing-cloud/engage-studio/channels/sms/shorten-links-in-sms-campaigns).

## Personalize with Liquid

Use Liquid to insert profile attributes at send time. For example:

```text
Hi {{ profile.first_name }}, your offer is ready.
```

Every variable in the message must have a corresponding output mapping. A message that references `profile.first_name` therefore requires a `first_name` mapping.

## Configure Output Mapping

Map the following values in the campaign activation:

- `phone_number` is required for delivery and must contain a phone number in [E.164 format](https://help.twilio.com/articles/1260803420489).
- Additional columns are required for each Liquid variable used in the message.
- Use the same column names in the mapping and the Liquid expression.


If a variable is not mapped, the rendered message may be incomplete or the activation may fail. See [Create an SMS Campaign](/ja/products/marketing-cloud/engage-studio/channels/sms/create-sms-campaign) for the activation steps.

## Related Requirements

- [Manage SMS Consent and Opt-Outs](/ja/products/marketing-cloud/engage-studio/channels/sms/manage-sms-consent-and-opt-outs)
- [Configure SMS Delivery Windows](/ja/products/marketing-cloud/engage-studio/channels/sms/configure-sms-delivery-windows)
- [Add UTM Tracking to SMS Campaigns](/ja/products/marketing-cloud/engage-studio/channels/sms/add-utm-tracking-to-sms-campaigns)