The optimal reminder cadence is short, consistent, and stops at two.
The two-message protocol
Reminder 1: 24 hours before
- Send window: 6-8pm.
- Content: patient name, doctor, exact time, clinic address with map link, reschedule link.
- Tone: warm, branded.
Reminder 2: 2 hours before
- Send window: 2 hours before slot, on the day.
- Content: short — "Your appointment with Dr. X is at 4pm today. Clinic phone: ___. Reply RESCHEDULE if you can't make it."
- This is the highest-impact reminder.
Why not three?
A third reminder lifts confirmation by ~2 percentage points but increases "spam" reports and degrades the doctor's WhatsApp sender reputation. The marginal patient added is far outweighed by the patients you annoy.
Edge cases
- First-time patients: add a welcome message immediately on booking, separate from the reminder cadence.
- Recurring chronic patients: skip the 24-hour reminder; send only the 2-hour one.
- Specialty premium slots: pair reminder 1 with a small confirmation deposit ask.
Templates
24h: "Hi {name}, this is a reminder of your appointment with Dr. {doctor} on {date} at {time}. Address: {map}. Reply RESCHEDULE to change. — {clinic name}"
2h: "{name}, your appointment with Dr. {doctor} is at {time} today. Clinic: {phone}."