The customer will receive an SMS reminder the day prior to their appointment, if the following conditions are met:
- At the time that you created the invoice and event, the customer was setup to receive SMS appointment notifications. This setting can be seen within the customer profile and can be changed by clicking 'Update Customer' and,
- On the day that the SMS notification is to be sent (i.e. the day prior to the appointment), the customer is still setup to receive SMS appointment reminders within their customer profile.