Thursday, 4.40pm. Your five o'clock texts to say something has come up and she can't make it. It's the second time this month a cancellation has landed inside the hour.
You have twenty minutes and your hands on somebody's shoulder. The waiting list lives in a notebook or in your head. You can start ringing round between techniques, or write the hour off. Most weeks it gets written off.
Can you charge for it?
You can have a cancellation policy and you can enforce it. What you can't do is make it disproportionate, or spring it on people.
Schedule 2 of the Consumer Rights Act 2015 lists terms that may be regarded as unfair. Paragraph 6 covers a term "requiring a consumer who fails to fulfil his obligations under the contract to pay a disproportionately high sum in compensation." Charging the session when someone cancels two hours out is arguable case by case. Charging three sessions, or the balance of a block, is the thing that paragraph was written about.
Spanish law mirrors that paragraph almost word for word, and adds something usefully concrete: consumer terms set in type smaller than 2.5mm don't count as legible at all. The millimetres don't cross the Channel, but the principle does. Written, legible, given before the first appointment, proportionate.
The prepaid block: a 14-day right most clinics don't know about
Nobody in the physio world writes about this one, and it catches out anyone selling blocks through a website.
The Consumer Contracts (Information, Cancellation and Additional Charges) Regulations 2013 give consumers 14 days to cancel a service bought at a distance. The excluded categories are gambling, banking, land, residential lettings, new-build construction, food delivered on regular rounds, package travel and timeshare; prescription medicines, NHS supply and passenger transport sit outside the cancellation rules too. Private healthcare is on neither list.
So a block of six sessions sold through your site carries a 14-day cancellation right. It's lost only once the service "has been fully performed", and only where the customer expressly asked for it to start and acknowledged they'd lose the right. Cancel halfway and reg. 36(4) has them paying a proportionate amount for what they used. A flat "no refunds on blocks" doesn't survive contact with that.
Spain is the mirror image: health services provided by a healthcare professional are carved out of the distance-selling rules entirely, so a Spanish physio block carries no cancellation right at all.
What it costs to advertise the gap on WhatsApp
Replying is free. Reaching out isn't.
Meta has charged per message since 1 July 2025, and service conversations have been free since 1 November 2024. Inside the 24-hour window from the patient's last message, the documentation is blunt: "All non-template messages are free." Utility templates delivered inside an open service window are free too.
Outside the window it changes. "We've had a 5pm cancellation" sent to somebody who messaged you on Monday is a paid template Meta has to approve first, and Meta's changelog lists a higher marketing message rate for the United Kingdom from 1 July 2026. The real ceiling isn't the price, though: it's your number's quality rating, which drops when people block or report you. Firing the gap out to thirty contacts every afternoon is the quickest way to get throttled. We went through the mechanics in WhatsApp Business API.
You are not going to stop the cancellations
Most last-minute cancellations are genuine: a temperature, a child, a shift that moved. Reminders and fees won't remove them, and anyone telling you otherwise hasn't worked a reception desk.
The number you can actually move is different: how long the slot stays empty. Separate metric, separate tool.
The only clean public figure here comes from the NHS rather than private practice, and it needs dating properly: of the 103 million outpatient appointments booked in 2021/22, 7.6% ended in a "Did Not Attend", and NHS England estimates that getting that to 2% would save £266 million. Your clinic's economics are nothing like an outpatient department's, but it's a useful reality check — that's the floor in a system sending reminders at industrial scale.
What a chat can't do in a clinic
It can't triage, and that's not our opinion — it's device classification. The EU guidance MDCG 2019-11 says hospital information systems, the ones handling admission, scheduling and billing, "are not in themselves qualified as medical devices". Booking is admin. But Rule 11 of the Medical Device Regulation classifies software "intended to provide information which is used to take decisions with diagnosis or therapeutic purposes" as class IIa at minimum. The moment your chat says "that sounds like mechanical low back pain, book the longer slot", it's the other side of that line. The same guidance closes the "it only searches my website" escape hatch: software isn't doing a "simple search" if it contributes to a medical purpose, and it names natural language processing specifically. Great Britain runs its own device regime and Northern Ireland follows the EU one; the line worth holding is identical either way. Booking is admin, triage is clinical.
It shouldn't decide who gets the slot. A course of physio is a course, not a series of loose transactions. Who comes in at five depends on where each patient is in their plan and whether there are intervals to respect. "First to reply" is not a clinical criterion.
It can't decide to charge, and won't cut your cancellation rate. It can restate the policy; whether to apply it this time is the clinician's call, with Schedule 2 in view. And the only thing it shortens is how long the slot sits empty — measure that, not the other one.
It isn't the clinician. Article 9(3) of the GDPR allows health data to be handled by or under the responsibility of someone bound by professional secrecy, and "my lower back has hurt for three weeks" typed into a chat is already special category data. The vendor is a processor and needs an Article 28 contract, not a tick box. The good news nobody mentions: recital 91 says processing patient data by an individual health professional isn't large-scale processing, so a small clinic normally doesn't need a DPIA. More on that here.
It won't fix a badly built diary. If the 24-hour rule is always waived, automation just speeds up the mess.
One more duty, brand new: from 2 August 2026 Article 50 of the EU AI Act requires anyone talking to an AI to know it from the outset. It's EU law, but it reaches you if you treat EU patients — and in a clinic it's worth doing regardless. It's what stops someone feeling deceived at the exact moment they're telling you something private. We wrote it up here.
What you can automate without crossing a line
- Answering whoever messages you, straight away, inside the window and at no per-message cost.
- Reminding and confirming, with the cancellation policy in plain sight.
- Re-offering the slot to a short list the physio has chosen, in the physio's order.
- Logging why people cancel — three months of that tells you whether the problem is the hour, the price or the parking.
- Handing over to a person the moment the conversation turns clinical.
Less impressive than "cut your no-shows by 50%", but it holds up in front of a patient and a regulator.
Zatio does that part: it answers inbound WhatsApp and web enquiries inside the window, confirms appointments and re-offers the slot when somebody cancels. It doesn't triage, doesn't choose which patient comes in, and says it's an AI in the first message. If you want to see how it would sit alongside your diary, here's the product.
This is general information, not legal advice. For your own cancellation policy, have someone look at your actual contract.