Ask a clinic owner what a missed appointment costs and you will almost always get the session fee back. Sixty pounds, ninety pounds, whatever the list price is.
That answer is wrong in both directions at once, which is a genuinely awkward combination. It overstates the loss on any single appointment, because the fee is revenue rather than profit and you never had all of it to keep. And it dramatically understates the annual figure, because it ignores that the costs behind the slot were paid regardless and that the same thing happens every week of the year.
Getting this number right matters for a practical reason. It is what tells you how much time, money and process change is worth spending on filling slots. Undercount it and you will keep treating cancellations as a minor annoyance. Count it properly and most clinics find it is one of the larger recoverable line items in the business.
Start with the costs that do not go away
The reason a fee is the wrong unit is that it is a gross number sitting on top of costs you have already committed.
When a slot exists in your diary, you have generally already paid for the room, whether you rent the space or own it and service a mortgage on it. You have paid for the practitioner, if they are salaried or on a guaranteed session rate. You have paid for reception cover for that hour. You have paid for the software, the insurance, the utilities and everything else that runs whether or not a patient walks in.
None of those costs reverse when the appointment does not happen. That is the whole point. An empty slot is not a quiet hour with no financial consequence, it is an hour of fully paid capacity producing nothing.
So the honest question is not "what was the fee" but "what would that hour have contributed". Which brings in the correction that goes the other way.
Then subtract what you did not have to spend
Against that, one category of cost genuinely does disappear when a patient does not attend. The consumables you would have used. The card processing fee on the payment. Any per-appointment cost that only occurs when someone is in the room.
For most physiotherapy, osteopathy and chiropractic appointments this is small, often a couple of pounds. For aesthetics it can be substantial, because the product going into the treatment may be a large share of the price, and an unused vial that stays in the fridge is a real saving.
There is one more subtraction that is easy to forget: if the practitioner is paid per patient seen rather than per session, you did not pay them for that hour either. That changes the arithmetic considerably, and it is worth knowing which model you are actually on before you calculate anything.
The figure you want
What you are after is the contribution of the slot: the fee, minus the costs that only occur when the appointment happens.
Slot contribution = fee - per-appointment variable costs
Worked through with illustrative numbers. Take a clinic charging £60 a session, with roughly £3 of consumables and card fees per appointment, and a practitioner on a fixed session rate.
£60 fee - £3 variable = £57 contribution lost per empty slot
The £57, not the £60, is what the empty hour actually cost. In this case they are close, which is typical for hands-on therapy, and it is why the fee is a rough but not disastrous proxy for a single appointment.
Now change one assumption. An aesthetics clinic charging £250 for a treatment where the product costs £90 and is not consumed if the patient does not attend:
£250 fee - £95 variable = £155 contribution lost
Still a serious loss, but a long way from £250. A clinic using the headline fee here would overstate the cost of each missed appointment by more than half, which leads to bad decisions about, for example, how aggressive a cancellation policy needs to be.
And change the practitioner model. If that £60 physio session is delivered by an associate paid 50% of what they bill, and they are only paid when the patient attends:
£60 fee - £30 associate - £3 variable = £27 contribution lost
Genuinely lower. The associate model transfers a real share of no-show risk away from the clinic, and clinics on that model should not be using the same mental figure as clinics with salaried staff.
The point of the three examples is that there is no universal answer, and the difference between them is large enough to change what you should do.
Now scale it, because that is where the number bites
A single missed appointment is a small problem. The reason this is worth any attention at all is what happens when you annualise it.
Take an illustrative three-practitioner clinic. Each practitioner runs 30 appointments a week at £60, so 90 appointments and £5,400 of booked capacity weekly. Variable costs of £3 an appointment, practitioners on fixed session rates, so £57 contribution per slot.
At a combined cancellation and DNA rate of 10%, nine appointments a week go unfilled:
9 slots x £57 = £513 a week
£513 x 46 working weeks = £23,598 a year
Roughly £24,000 of contribution, from a clinic that never had a bad month and never lost a patient. It simply never filled the gaps.
The reason this figure surprises people is that it never arrives as a bill. It shows up as nine slightly quiet afternoons a week, spread across three practitioners and five days, where nothing visibly goes wrong. There is no moment at which anyone sees £24,000 leave.
Run the same calculation with your own numbers. The formula is:
Annual cost = weekly appointments x empty rate x contribution x working weeks
Use your real appointment volume, your real rate, and a working year that reflects your actual closures and leave rather than 52 weeks.
What portion of that is actually recoverable
Here is where a lot of writing on this subject stops being useful, because it presents the full annual figure as if it were sitting there waiting to be collected. It is not, and pretending otherwise leads to disappointment and abandoned processes.
Split the number in two.
The no-show portion is not recoverable. By the time you know the patient is not coming, the slot has passed. That part is addressed by prevention, which is a different discipline with a well-evidenced toolkit, set out in our guide to ten proven ways to reduce patient no-shows.
The cancellation portion is partly recoverable, and how much depends almost entirely on notice. A cancellation three days ahead is very likely fillable. One with a few hours of notice is fillable if you move quickly. One with twenty minutes of notice generally is not, whatever system you run.
So the realistic prize is a decent share of the cancellations that arrive with a few hours or more of warning. For the illustrative clinic above, if six of the nine weekly empty slots are cancellations rather than DNAs, and half of those could realistically be filled, that is three slots a week:
3 x £57 x 46 = £7,866 a year
Around £8,000, against no new marketing spend, no new patients and no price increase. That is a more honest number than £24,000, and it is still comfortably worth building a process around.
The number nobody measures
There is one more calculation, and it is the one that makes all of the above actionable rather than theoretical.
Take last month. Count the appointments that were cancelled. Count how many of those slots were subsequently booked by someone else. Divide the second by the first. That is your fill rate.
Almost no clinic knows this figure, because practice management systems will happily show you a DNA rate and generally will not compute this one for you. The consequence is that the recoverable half of the problem is invisible while the unrecoverable half is on a dashboard, which is a good explanation for where clinic attention tends to go.
If your fill rate is low, the gap between it and what it could be, multiplied by your contribution figure, is the actual size of the opportunity. That is the number worth acting on, and the practical steps are in our guide on how to fill a last-minute clinic cancellation.
Two things worth remembering
Capacity is the real product. A clinic sells hours of practitioner time. You have a fixed number of them, they cannot be stored, and an hour that passes unused is gone permanently in a way that unsold stock is not. That framing makes the priority obvious: protecting the utilisation of existing capacity is almost always cheaper than acquiring the demand to justify more of it.
Precision matters less than direction. If your contribution figure is £57 and you calculate £52, nothing changes about what you should do. If you have been using £0, because nobody ever worked it out, everything changes. Get to a defensible number and move on.
For the wider picture of why slots go empty and what to do about it, see our guide on how to recover revenue from cancelled appointments.
How ShowUp thinks about this
ShowUp provides SMS appointment reminders for UK private healthcare clinics, and the recovery capability described across this cluster is what it is being built around next. The reasoning is exactly the arithmetic above: prevention addresses the part of the loss caused by forgetfulness, and everything left over is capacity sitting idle with someone available who would have taken it.
ShowUp is built on the view that a freed slot should prompt a considered approach to a suitable patient immediately rather than waiting to be noticed, that accepting should take a single action, and that a person at the clinic should confirm anything before it reaches the diary.
If you have run these numbers for your own clinic and want to talk about the gap, send us an email.
About the author
Will Kirk is the founder of ShowUp Software Ltd, a UK company that makes ShowUp: software that helps private healthcare clinics recover revenue from cancelled and missed appointments by offering freed slots to a waiting list by SMS, with automated appointment reminders included. ShowUp works alongside Cliniko. Based in Nottingham. ICO Registered: ZC159538. Company Number: 17228859.
Sources
- British Journal of General Practice: Text message reminders for healthcare appointments: a systematic review
- NHS England: Outpatient attendance and DNA data