CentriWebAn appointment reminder text works best as two short SMS messages: one a few days ahead that asks the client to confirm or change, and one on the day that gives the time and address. Each text has a one-word reply and a rebook link, so a client who cannot come tells you in time to offer the slot to someone else.
This guide sets out the timing, the exact wording, how replies are handled and the checks that stop a reminder going out for an appointment that has been cancelled.
The trigger and what the system needs to know
An automated appointment reminder is driven by your calendar, so nobody has to remember to send it. When an appointment is booked, the system records four things: the client’s mobile number, the start time, the service and the person they are seeing. Everything else flows from those.
The steps are:
- A booking is created or changed in the calendar.
- The system works out the send times by counting back from the start time.
- Before each text, it checks the appointment still exists and has not been cancelled or moved.
- It sends the message and records the reply against the booking.
- A reply of “confirm” updates the status. A reply asking to change creates a task or sends a rebook link.
Step three is the one people forget. If your system does not re-check the appointment at send time, someone who cancelled on Tuesday gets a reminder on Thursday, which looks careless.
Two reminders and when to send them
One text is easy to miss, and three feels like nagging. Two is a good default for most practices and service businesses.
| Reminder | When | Job it does |
|---|---|---|
| First | 2 to 3 days before | Ask the client to confirm or change while there is still time to refill the slot |
| Second | Morning of the day, or 2 to 3 hours before for afternoon bookings | Time, address, parking, what to bring |
Adjust to your business. A dental or physio practice with a short-notice waitlist benefits from the earlier prompt. A mobile trade visit may only need the day-before text and a “we are on our way” message. For appointments booked less than two days out, skip the first reminder and send only the second.
Do not send before about 8am or after about 8pm. A text at 6am to confirm a 2pm appointment will not be forgiven by the client.
Sample appointment reminder text wording
Keep each message to one screen, name the business at the start and use a first name. Avoid emoji and shouting capitals. These templates are a starting point.
First reminder with confirm and change options:
Hi [First name], this is [Business]. You’re booked with [Person] on [day, date] at [time]. Reply C to confirm or R to reschedule. Or change it here: [link]
Day-of reminder:
Hi [First name], a reminder that your appointment with [Person] is today at [time] at [address]. Parking is [detail]. If you can no longer make it, please tell us here: [link] or call [number].
After a “C” reply:
Thanks [First name], you’re confirmed for [day] at [time]. See you then.
After an “R” reply:
No problem. Pick a new time here: [link], or reply with two days that suit and [Name] will find a slot.
A reply path matters as much as the first text. If the client can only receive, a cancellation arrives as a no-show.
How to handle replies without a person watching all day
Replies fall into predictable groups, and a simple set of rules can sort them.
- C, Y, Yes, Confirm: mark the booking confirmed and send the thank you.
- R, Change, Reschedule, Cancel: send the rebook link and create a task. If the client cancels, release the slot and offer it to your waitlist.
- STOP: record the opt-out, stop all texts to that number and confirm once. This must work every time.
- Anything else: a question, a photo, a complaint. Route it to a named person during business hours.
“Anything else” is the group where automation goes wrong, because a client writing “I’m running ten minutes late” gets a robotic reply. Make sure unrecognised replies go to a human instead of getting an automatic “sorry, I didn’t understand”.
The rebook link: turning a cancellation into a booking
When someone cannot attend, the worst outcome is silence. The best outcome is a new time booked in the same moment. A link to your online booking page that shows real availability lets the client choose without a phone call. If you cannot offer that yet, a reply asking for two preferred days still beats losing contact.
Cancellation also creates an opening. If your system keeps a waitlist, a freed slot can trigger a text to the next person: “A time has opened up on [day] at [time]. Reply Y to take it.” Whoever replies first gets it, and you tell the others it is gone.
For the longer picture on cutting missed appointments, including deposits and cancellation policies, see our guide on how to reduce appointment no-shows. For clients who have drifted away between visits, patient recall and reactivation is the companion process.
Privacy, consent and rules
Keep the text itself light on detail. A message that says “your appointment with Dr Lee about your test results” tells anyone who sees the phone more than it should. Name the business, the time and the place, and leave the reason out unless the client has asked for it.
Whether a reminder counts as a marketing message is a legal question, and the rules on consent, identifying the sender and opting out differ between countries, and they change. In Australia the Spam Act and the regulator, the Australian Communications and Media Authority (ACMA), set them. We could not open the ACMA pages when writing this, so read them yourself for your situation, and our summary of SMS rules for Australian small businesses covers the basics. If you add a promotion to a reminder, the message becomes marketing and different expectations apply, so keep the reminder as a reminder.
Health providers, lawyers and others with confidentiality duties should also check what their professional body expects about patient or client contact details and messages.
Checks before you switch it on
A reminder system fails quietly. Nobody complains when a text does not arrive, they just do not turn up, so test it deliberately.
Test with your own phone and a handful of staff bookings for a week before real clients are included.
- Time zones. If you serve clients across states or countries, confirm the times shown match where the appointment is, and not the location of the server.
- Daylight saving. Book test appointments across a clock change and check the reminders.
- Number format. Mobiles stored with spaces, a missing leading zero or a landline will fail quietly. Run a report of bookings with no valid mobile.
- Cancelled and moved bookings. Cancel a test appointment and confirm no text goes out.
- Duplicates. If your booking tool and your CRM both send reminders, clients get two texts. Pick one.
- Group and recurring bookings. A weekly appointment should not trigger a long confirm request every week. Confirm the first and remind for the rest.
Look at the results monthly. The numbers worth tracking are how many bookings were confirmed, how many were cancelled with notice, and how many no-shows remain. Do not rely on a figure from a vendor or a blog for what reminders achieve. Your own before and after is the only number that matters for your business.
Where to build it
Most booking tools and practice management systems include basic reminders, and for a single location with a standard calendar that may be enough. Look at what yours does before building anything.
A custom set-up makes sense when reminders must read from several calendars, when replies need to update your CRM, or when you want a waitlist to refill cancelled slots automatically. CentriWeb builds many client systems on GoHighLevel and most client automations in n8n, and we can set up the whole flow for health and fitness and other appointment-based businesses. If the tool you already pay for covers the two-text pattern above, use it.