Overview
Understanding the intricacies of SMS segments and the associated costs is essential for optimizing your messaging strategy. This article will clarify what SMS segments are, how they impact message delivery, and provide insights into the costs involved in sending SMS campaigns.
Next, learn about SMS Marketing Best Practices - How to Maximize Engagement and Conversions.
Segments in SMS
What is a segment?
In SMS communication, a segment refers to a single unit of a text message, which can either be sent on its own or as part of a longer message. The number of characters in a segment depends on the type of encoding used. The most common encoding, GSM-7, allows for up to 160 characters per segment. This encoding covers most Latin characters, numbers, and basic symbols.
When you send a long message, it’s broken into multiple segments, each of which is sent separately. The first segment contains additional information, similar to a header on a letter, reducing the available space for the message. Subsequent segments also include some additional data, meaning each segment has slightly fewer characters available for the actual content.
Note: If your message contains emojis or special characters outside the GSM-7 character set, the encoding switches to UCS-2, which supports a wider range of symbols but reduces the segment length to just 70 characters.
Important considerations:
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Opt-out information: For compliance with marketing regulations, a legal notice informing recipients how to opt-out (e.g., replying ‘STOP’) is automatically appended to each SMS. This notice takes up 16 characters, reducing the available space in the message segment.
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Multi-segment messages: When an SMS spans more than one segment, the character limit per segment decreases slightly to allow for linking the message parts together:
- GSM-7: From 160 characters down to 153 per segment.
- UCS-2: From 70 characters down to 66 per segment.
This reduction occurs because each segment requires a header containing metadata like the segment number, adding 7 bytes for GSM-7 and 4 bytes for UCS-2.
Segment Costs
Each SMS message is typically divided into segments, and the total cost of your campaign will depend on the number of segments used. A single message can use one or more segments, especially when it includes special characters, emojis, or exceeds the standard character limit. The cost of sending SMS messages is based on the number of segments. Each segment costs $0.0225, and the total cost depends on how many segments are used in your campaign.
Note that In addition to segment-based fees, the campaign fees include a base fee of $20.
Estimated Costs
When preparing your SMS campaign, you’ll see an ‘Estimated Cost’ side tab that provides an approximate total cost. This estimate calculates the number of segments based on the longest variable (i.e., recipient names) in your audience. However, the actual cost is calculated during the final step, ‘Confirm & Pay’, where the exact length of each variable is considered for every recipient.