An empty slot costs twice: once for the time you paid for, and again for the client who never rebooks because they were too embarrassed to call. A well-timed reminder solves most of the problem.
Timing matters more than wording
A reminder sent 24 hours ahead works best: early enough for the client to cancel and for you to fill the slot, late enough not to be forgotten.
Sent a week ahead, the message is lost. Sent an hour ahead, it arrives too late for the slot to be taken by anyone else.
One reminder, not three
The temptation is to send at a week, at a day, and on the morning itself. In practice the second and third add little and start to irritate. One message, at the right moment, is usually enough. The exception is services that need preparation, where a second message carrying instructions stands on its own merits.
What the message must contain
- Who is writing. A message from an unknown short code gets ignored. Put the practice name in the first few words.
- The exact date and time. "Tomorrow" on its own is not enough, because the message may be read the next day.
- What to do if they cannot make it. A phone number to cancel on turns a no-show into a free slot.
Respect the hour
A reminder at 22:30 does more harm than good. Set a sending window, for example between 09:00 and 20:00, and messages that would fall outside it are postponed automatically to the first permitted hour.
What happens when an appointment moves
This is the case that destroys trust: the client receives a reminder with the old time after the appointment was moved. The rule is simple: a changed appointment must cancel the old reminder and schedule the new one automatically, without anyone having to remember to do it by hand.