SMS reminders send a text message to each customer 24 hours before their appointment. Customers opt in during booking by entering their phone number; if they do not opt in, no SMS is ever sent and no phone number is stored. The feature is available on Pro and Advanced plans.
Use SMS reminders when no-shows are costing you real time — text messages get seen faster than emails. They run alongside the existing confirmation and reminder emails; SMS does not replace email, it adds a second channel for customers who opted in.
1. Turn on the organization toggle
Open Settings → Organization → Preferences. As the owner, turn on "Send SMS reminders". Until you do, the phone opt-in does not appear on the booking page and no SMS is sent.
Turning the toggle off again stops new opt-ins from being collected; existing consented phone numbers stay on their appointments, but no new reminders are sent.
2. What the customer sees
On the booking form, under name and email, customers see a "Receive SMS reminders" checkbox and a phone number field. The phone field stays disabled until the customer ticks the checkbox — that is the explicit consent step.
If the customer does not opt in, the phone number field stays empty and disabled. The booking still goes through normally; no SMS is sent, no phone is stored.
3. When the reminder goes out
A background job scans appointments every 15 minutes and sends a reminder to each consented customer 24 hours before their appointment time. Bookings made less than 24 hours in advance do not receive an SMS reminder — the cron window has already passed.
Each appointment gets at most one SMS reminder. If delivery fails (carrier outage, bad number), the system does not retry — the customer falls back on the email reminder.
4. What the message says
The message is localized to the customer’s locale and reads:
Reminder from {org}: {service} is tomorrow at {time}. Need changes? Use the link in your confirmation email.
The SMS itself does not carry a manage link — to keep the message short and avoid carrier link-shortener filtering. If the customer wants to reschedule or cancel, they tap the link in the confirmation email they already received when they booked.
5. Customers can change their mind
During reschedule, the customer sees the same SMS opt-in. They can update their phone number, leave it unchanged, or untick the consent checkbox. If they untick it, the phone number is cleared from the appointment.
6. Privacy and storage
- Phone numbers are only stored when the customer explicitly opts in. No phone number arrives at Zimun without a corresponding consent timestamp.
- The phone number lives on the private side of the appointment record, alongside contact email — not on the public appointment surface.
- Phone numbers are not exposed via the standard public booking API.
- Withdrawing consent clears the phone number from the appointment record.
7. Plan requirement
SMS reminders are available on Pro and Advanced plans. On Free, the "Send SMS reminders" preference is hidden and the booking-page opt-in does not appear.
Downgrading to Free disables future SMS delivery without losing any customer data already stored. If you upgrade again later, reminders resume for any appointment that still has a future start time and a consented phone number.
8. Summary
Turn on the organization preference, let each customer opt in by ticking the checkbox during booking, and Zimun sends the reminder 24 hours before the appointment. Consent is explicit, the message is localized, and customers reschedule or cancel through the link in the original confirmation email.