Character limits of an SMS and the effects on pricing in Campaigns
Understanding the character limits of an SMS and its impact on pricing is crucial for efficient campaign management. This article will help clarify these elements to optimize your messaging strategy.
What's the Length of an SMS Message?
A standard SMS can contain up to 160 characters when using the GSM-7 character set. If your message exceeds 160 characters, it will be sent as a multi-part (concatenated) message, with each part accommodating up to 153 characters.
Certain characters, such as | ^ € { } [ ] ~ , are considered extended in the GSM-7 character set and require two 7-bit bytes instead of one. So, an SMS containing a single € sign, for example, can only have 159 other characters.
If you use special characters like Cyrillic, Chinese, emoji, or specific accented Latin characters, your message will be sent as a Unicode message (UCS-2). A single Unicode message is limited to 70 characters. In multi-part messages, each part can hold 67 characters, with emoji consuming 2 characters each.
Character Set | Single Message | Multi-part Message |
---|---|---|
GSM-7 | 160 | 153 |
Unicode | 70 | 67 |
The Campaigns editor shows you how many messages your text will use as you compose it.

Effect of SMS Length on Pricing
For those using Campaigns within the Mobile Marketing Cloud, standard SMS pricing is available here: https://www.cm.com/pricing/sms/. This pricing remains consistent across Basic, Advanced, and Pro packages, although custom pricing may apply for specific destinations and can be found in your contract.
In the Campaigns editor, you can view an estimated cost for the entire campaign in the lower right corner, calculated based on the number of messages and recipients. Once the campaign is sent, a cost estimate is available on the campaign's statistics page. Please note, both figures are estimates. The final cost is influenced by your pricing rates at invoicing time and the effect of merge tags on message length.


How Do Merge Tags Affect SMS Length?
When using merge tags linked to an address list in your campaigns, the message length (and therefore the price) can vary for each message. The Campaigns editor cannot predict the full impact of all merge tags before sending.