A missed appointment costs a whole round
Hacot & Co services water softeners in people's homes. When the technician finds nobody in, the drive was for nothing, and the slot cannot be filled at the last minute: a service visit is planned weeks ahead, together with the other addresses in the area.
As of 13 September 2026, the application we built for Hacot & Co was tracking 674 appointments, and only 2.2% had been missed. For comparison, the only large-scale public figures come from healthcare in France, where patients book online.
| Where | Missed appointments |
|---|---|
| Dentists, booked on Doctolib | 6.2% |
| Medical specialists, on Doctolib | 4.5% |
| GPs and paediatricians, on Doctolib | 3.4% |
| Hacot & Co, water softener servicing | 2.2% |
Doctolib: analysis of its own data from February 2023, quoted in the French National Assembly on 24 October 2024. Hacot & Co: missed appointments measured in the application on 13 September 2026.
A medical practice and a servicing round are not directly comparable. But the order of magnitude is the same, and every point counts when an absence costs a trip.
What the customer receives, and when
Everything starts from the servicing calendar. The application knows when each softener is due for servicing, and it tells the customer well in advance. Each message goes out by SMS and by email at the same time.
| When | Message |
|---|---|
| A month before the service is due | An invitation to book |
| Two weeks before, if no reply | A second invitation |
| As soon as the customer books | An acknowledgement |
| When the office validates | The confirmation, with day and time |
| The day before | The reminder, with day and time |
| No booking after the due date | Follow-ups at 30, 45 and 60 days |
Message schedule of the Hacot & Co application, read from its code on 8 November 2026.
One rule comes before all the others: a customer who already has an appointment gets no more invitations or follow-ups. One message too many does more harm than one message missing.
The reminder does not do it alone
SMS reminders work, and this has been measured. A 2013 Cochrane review of eight trials and 6,615 patients found 78.6% of appointments kept with an SMS reminder, against 67.8% with no reminder. A phone call does barely better, at 80.3%, and two of the trials found it costs more per kept appointment.
At Hacot & Co, three other choices matter as much as the reminder.
The customer picks the day
The application does not impose a date. It offers the days when the technician is already working nearby, the customer picks one, and the office validates it. The appointment falls on a day that suits the customer, and the round stays grouped.
Cancelling is easy
Since September 2026, customers can cancel online up to 24 hours ahead. A cancellation the day before gives the office time to rearrange the day. A closed door does not.
The office stays in control
Not every customer uses the online space. Many still phone, and the office books their appointment itself. The confirmation and the day-before reminder go out for those appointments too.
What an SMS costs, and the character trap
At Twilio, the provider we use for Hacot & Co, an SMS to France costs $0.0798 per segment as of 8 November 2026. For 100 appointments a month, with a confirmation and a reminder each, count 200 texts, about $16 a month.
The word that matters is "segment". An SMS holds 160 characters, as long as it sticks to the basic SMS alphabet. An emoji, a curly apostrophe or a French letter such as "ê" is not part of it: a single one drops the segment to 70 characters, and the same message is billed two or three times. This is why Hacot & Co's texts are written without accents.
The date is the other trap. Written out in full in French, "mercredi 30 septembre 2026", it pushed two messages over 160 characters in our measurements, so they went out as two texts. A short date, "mercredi 30/09", brings them back under the limit. Test your messages with the longest date of the year, not today's.
What to set up before the first send
- Clean mobile numbers. In international format, without spaces. A landline cannot receive texts, so email has to take over, as it does in the Hacot & Co application.
- A short message. The company name, the day, the time, a link for details. Nothing else.
- A service message, not an advert. A reminder is about an appointment already booked. Slip an offer into it and it starts to look like marketing, which comes with stricter rules, consent first among them.
- An easy way to cancel or move. Without it, the reminder only confirms the absence.
- Delivery tracking. "Sent" means the provider accepted the message, not that it arrived. The Hacot & Co application records the delivery receipt of every text and every email, so when a customer says nothing arrived, the office can check.
Where to start in your business
If your appointments already live in a calendar or a software tool, reminders can often be plugged into it without changing tools. That is an automation job, not new software. See our automation work
If planning is still done by hand, between a spreadsheet, the phone and a map, the reminder is only one piece. At Hacot & Co, it is part of an application that groups service visits by area, offers days to the customer and puts the technician's day on their phone. Read the case study
Sources
The missed appointment rates come from Doctolib's analysis of its own data from February 2023, quoted in the explanatory statement of amendment no. 1103 to the 2025 French social security financing bill, tabled in the National Assembly on 24 October 2024. The effect of reminders comes from the Cochrane review "Mobile phone messaging reminders for attendance at healthcare appointments" (Gurol-Urganci et al., December 2013). The SMS price comes from Twilio's pricing page for France, and the segment rule from its documentation.
Pages consulted on 8 November 2026. SMS provider prices change often.
