How to send text message reminders to clients from Google Calendar

Google Calendar is good at reminding you. It is not built to remind the person you are meeting. If your client is not on your calendar they get nothing, and if you add them as a guest, what they get is an email invitation — not a text on the morning of the job.

This guide covers why that is, the realistic ways around it, and how to send a client an SMS reminder straight from a calendar event.

Why Google Calendar will not text your clients

Calendar's notifications are for the people using the calendar: pop-ups on your devices and emails to you. Guests you invite receive an email invitation and, if they use Google Calendar themselves, their own notifications.

Google did once offer text-message notifications, but switched them off on 7 January 2019, replacing them with in-app and email notifications. Even then they were notifications for the calendar's own user, not a way to message someone else. There is no setting to turn back on.

Your options

There are three honest routes.

• Build it yourself. An automation tool or a Google Apps Script can watch your calendar and hand messages to an SMS provider. It works, and for a handful of appointments it can be cheap. You then own the parts that go wrong: finding the phone number in each event, formatting it, timing the message, handling people who ask you to stop, and noticing when it quietly breaks.
• Move to a booking system. Most online booking tools send reminders. The cost is that your bookings now live in their calendar rather than Google's, and your staff have two places to look.
• Add reminders to the calendar you already use. That is what Calendar Force does, and the rest of this guide walks through it.

Step 1: Put the client's number in the event

The reminder goes to the number in the event description. Write it with a tag — Mobile: 0491 570 156 — and that is the number used. Without a tag, the description is scanned for anything that looks like a phone number, which is why the tag is worth the habit: it stops an invoice or account number being mistaken for a mobile. Numbers identified as landlines are skipped, because a landline cannot receive an SMS.

Step 2: Write the message once

Reminders come from a message template. You write the wording once, and each client receives it with their own appointment details filled in.

The details go in through placeholders — short tags in curly brackets. Every placeholder is optional: keep the ones you want, delete the ones you do not, and put them wherever they read best in your wording.

• {event_name} — the event title from your calendar
• {event_date} — the date, e.g. 15/09/26
• {event_time} — the start time, e.g. 10:30 am
• {event_datetime} — date and time together, e.g. 15/09/26 at 10:30 am
• {time_until} — how far away it is, e.g. in 2 hours
• {business_name} — your trading name, from your business details

Check what your event title says

{event_name} sends the whole event title, exactly as it is in your calendar. If you title events with the client's name and their group code, the code goes in the text too. An event titled Jane Citizen (ABC) with the default wording sends:

Reminder: Jane Citizen (ABC) starts at 10:30 am on 15/09/26

If you would rather clients did not see the code, delete {event_name} from the template and write the message without it — for example:

Hi, this is {business_name} confirming your appointment at {event_time} on {event_date}.

The default wording

If you do not write your own, Australian numbers get Reminder: {event_name} starts at {event_time} on {event_date}, and US numbers get a version that also carries the opt-out line US carriers expect. Treat either as a starting point and edit it like any other template.

Step 3: Choose when it goes out

A template also carries its timing, as minutes before the event: 1440 is the day before, 60 an hour before, and a template can hold several, so 1440, 60 sends both. When you create a template in the add-on you can also describe the timing in plain English — “the day before and an hour before” — and it is converted into minutes for you to check before saving.

Step 4: Set the reminder on the event

Open the event in Google Calendar and open the Calendar Force panel beside it. Set a reminder, choose the template, and — if this one client needs different wording — edit the message for that event alone without changing the template.

That is the whole job for one appointment. For a week of them, arm the whole date range in one pass instead: how to send reminders for a whole week of events at once.

What your client receives

In Australia, the message arrives from the sender name CalForce. A sender name cannot receive replies, so a client who wants to reschedule needs another way to reach you — put your number in the wording if that matters for your business.

In the United States, it arrives from a US phone number, starting with “CalendarForce:” and ending with “Reply STOP to opt out.” Both are added automatically, as US carriers require, and both count towards the message length. US carriers also require a record that the client agreed to receive texts before the first one: the Calendar Force panel asks you to record how consent was obtained, once per number, and will not arm a reminder to a US number until you have.

SMS reminders are live for Australian and US numbers. For other countries, check with us before relying on it.

What it costs

Reminders use SMS credits: one credit per SMS segment. A message of up to 160 plain characters is one segment; emoji and some special characters shorten a segment to 70 characters, so a single emoji can double the cost of a message. Packs start at AUD 9.99, and a reminder that cannot be sent at all — no number, a landline — does not use a credit. Full pricing.

After it is sent

The Reminders page in the web app shows every reminder as pending, sent or failed, with the reason when one fails. “Sent” means the carrier network accepted the message; delivery to the handset itself is not currently reported.

Only text people who expect it

A reminder for an appointment a client booked with you is a message they want. Unsolicited marketing is not, and SMS is regulated in most countries. A US client can reply STOP, and that is honoured automatically. An Australian client cannot reply to CalForce, so they will tell you directly — remove their reminders and take their number out of the event description.

Summary

1. Google Calendar cannot text clients; its text notifications ended in January 2019.
2. Put the client's number in the event description with a Mobile: tag.
3. Write one template, keeping only the placeholders you want — leave out {event_name} if your titles carry group codes.
4. Set the timing as minutes before the event.
5. Arm the event from the Calendar Force panel — or a whole week at once.

Calendar Force is a Google Workspace Marketplace add-on plus a web app, built for service businesses that already run their work out of Google Calendar. See pricing or start free.