Why data fields might increase SMS cost

Every data field value you store might be a different length. This can affect SMS message length, and therefore, cost.

Laura Russell avatar
Written by Laura Russell
Updated over a week ago

Adding personalisation to your SMS messages is a great way to communicate directly with your customers – in fact, due to the personal nature of SMS, most users expect a higher level of personalisation. But before using your data fields, it's essential to be aware of how personalisation can increase the overall message length and cost of your SMS sends.

How data fields affect SMS length and cost

One SMS message segment has a maximum character count of 160 characters. Every time the character count of the SMS message is more than 160 characters, it is sent and charged as two SMS message segments – these segments are combined and appear as one message on your customer’s phone, but they are still billed individually.

Additional segments vary in their maximum character count. Learn more in SMS message length and Unicode.


You've written a 155-character SMS message to send to your contacts. You've started the message with some personalisation by using the First name data field. On the message preview; it looks like this:


At this point, we can't give you an accurate character count for your message, because the character count is different for every contact depending on the length of their first name.

To keep things simple, imagine you only have two contacts in your list: Amar and Charlotte. Because Charlotte has over double the number of characters in her name, the SMS message to her has more characters. The breakdown below demonstrates how the character count, message count, and overall billing cost is affected by the personalisation added to these two SMS messages.

SMS to Amar

SMS to Charlotte

Message length:



Maximum characters per message:




Original message (155) + Amar (4)

Original message (155) + Charlotte (9)

Total messages sent:



Total messages billed:



To sum up

Don't avoid using personalisation, but be aware of the possible additional cost when adding data fields.

If you do use personalisation, try to keep messages short and know the maximum length of the data fields you're adding. If you can't keep it short, be happy that although it may cost more, adding the personal touch can make your message more effective.

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