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SMS more commonly called "text messages" are sent in 160 character segments. Modern phone assemble multiple segments into what appears to be one message. To allow for a larger message about upcoming events we increased the maximum limit of 160 characters to 320. The "SMS Cost" indicates when the combined message and the student stats exceeds 160 characters, requiring a second segment to be sent. The SMS cost shows the number of credits required to send each SMS notification.
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ADMIN SETTINGS >> Balance