A SMS message is made up of one or multiple message segments depending on how long or short the SMS message is. Alertline SMS' are billed on a per message segment basis. A message segment is roughly around 152 characters in length depending on the message content i.e. emoji's take up more characters than plain text. If a SMS message was over 400 characters in length the SMS message sent by Alertline would be made up of three message segments.
We advise that the SMS message is kept within one message segment or as short as possible. If a SMS message is sent out to a large number of subscribers the total billable SMS message segments can quickly escalate as each subscriber would receive a SMS message consisting of X amount of message segments. For example, if the SMS message spans over three segments and 10,000 subscribers are sent the SMS message, the Alertline would be billed for 30,000 message segments.
Here is the calculation that Alertline uses
number of subscribers X number of message segments = number of billable sms messages
I will now add the data from the above example into the calculation.
10,000 subscribers X 3 message segments = 30,000 billable sms messages
When writing the SMS message the console will give you real time information relating to how many message segments the SMS message would use.