By configuring Setting> Marketing> Reservation Reminder> Automatic Delivery> Full Automatic, you can automatically send a booking reminder SMS from the server at the set time.
In order to send this SMS, you need to purchase SMS Credits. This article is about the consumption t of that SMS credit.
One SMS message consists of one or more "Segments".
One SMS segment is if the message inludes,,,
Half-width alphabet and numbers only : 153 characters
Contains other characters : 70 characters
SMS credits are consumed for this "Segment".
You can check how many characters are used in the message template, and whether the content of the current template is based on 153 characters or 70 characters, in Settings> Marketing> Reservation Reminder> Templates.
Below is an example where similar messages have different numbers of segments.
The template above contains Emoji, so 70 characters are treated as one segment.
As a result, the upper template has two segments (77 characters for 70 characters per segment), while the lower template has one segment (74 characters for one segment per 153 characters).
In fact, in addition to the template, characters such as the customer's name are added and the total number of characters increases, and in the case of the upper template, there may be a total of 2 to 3 segments, but the lower template will probably fit into one segment.
In order to reduce the consumption credit, it is recommended not to use non-alphanumeric characters and to make the template as simple as possible.
This is not the TapStyle specification, but the standard behavior of SMS. For example, this external link explains the same thing. https://www.twilio.com/blog/2017/03/what-the-heck-is-a-segment.html