Nope. You can create an appointment with only an email address OR phone number. No need to enter both unless you want to. You can choose whether you want the person to be reminded by email or text message, both, or not be reminded at all.

If you want to do your appointment reminders by text only, then you have that option. You also have the option to do your appointment reminders by email only, or you can use both text and email.

Your customer does not need to have the GoReminders app installed.