Use a 13-week rolling forecast: one row per week, money expected in, money going out, and the running bank balance, updated every Monday. For a private clinic the forecast has to show four things a profit figure hides: the December and August troughs, the weeks-long lag on insurer payments, the 31 January tax bill, and annual costs such as indemnity, registration and professional body fees. Most clinics that run short of cash are profitable on paper; the forecast tells you which week the money runs out, early enough to do something about it.
Profit tells you whether the practice works over a year. Cash tells you whether you can pay the room rent on Friday. The two diverge most in exactly the weeks when private practice is quietest, and that is the gap a forecast is for.
Why 13 weeks?
Thirteen weeks is one quarter: long enough to see a tax bill or a seasonal dip coming, short enough to predict with reasonable accuracy. A forecast for the next twelve months is mostly guesswork beyond month three. A forecast for the next fortnight is too short to change anything.
Rolling means you drop the week just finished and add a new week at the end, every week. You always look a quarter ahead. Keep a separate twelve-month view of the big, predictable lumps (tax, annual renewals, planned equipment) so they appear in the 13-week window in good time.
When are private clinics quietest?
December and August, by a distance, and January is weaker than most owners expect. The UK Private Practice Barometer 2026, a self-reported survey of 715 UK MSK clinic owners by HMDG, asked owners which months were their busiest and quietest. For physiotherapy the net seasonality scores (the percentage naming a month as busiest minus the percentage naming it as quietest) were:
| Month | Net seasonality score, physiotherapy |
|---|---|
| October | +161 (busiest) |
| March | +143 |
| January | -24 |
| August | -155 |
| December | -188 (quietest) |
In London, 62.5% of clinics named August as their quietest month. The January figure is the surprise. The "new year, new me" surge that gyms see does not reach physiotherapy: the Barometer's explanation is that post-Christmas finances push bookings back to February and March.
Plan for a weak January, not a busy one. That matters more than it sounds, because January is also the month the tax bill falls due.
These are self-reported scores, not booking data, and your own diary is a better guide than any national average. Pull last year's appointments by week from your practice software and use the shape, not the survey, in your forecast.
How long do insurers take to pay?
Weeks, not days, so insured sessions belong in the forecast in the week the money arrives, not the week you treated the patient. Bupa's physiotherapy network terms say it pays by BACS no later than seven days after an invoice is "cleared by us for payment", and ask providers not to chase until 45 days after the invoice date. Invoices must also be submitted within six months of treatment or they are rejected, and you cannot then bill the patient.
Two consequences for the forecast:
- The December trough reaches your insurer income in February. Fewer insured sessions over Christmas means fewer remittances about six weeks later, just as self-pay income is recovering.
- Delays in your own invoicing are delays in cash. An insurer cannot pay an invoice you have not sent. Submit weekly.
Other insurers set their own terms. Use your own history: for each insurer, the median days from session to payment over the last six months is the right lag to forecast with.
What goes in the forecast?
Every receipt and payment, in the week it hits the bank.
Money in:
- Self-pay sessions, usually paid on the day
- Insurer remittances, lagged as above
- Package or block-booking payments, which arrive up front and then cover several future weeks of appointments with no new cash
- Other income: class fees, sports club contracts, report writing for solicitors or case managers (often on 30 to 60 day terms)
Money out:
- Room rent or licence fee, usually monthly
- Drawings or salary, and any associate payments
- Software, phone, card processing fees
- Tax: for sole traders, 31 January and 31 July; for companies, corporation tax nine months and a day after the year end, plus PAYE each month if you run payroll
- Annual and occasional costs (below)
The running balance: opening balance plus money in minus money out, carried to the next week. The single number that matters is the lowest balance in the 13 weeks.
Which annual costs catch people out?
The ones you pay once a year and forget about for the other eleven months. For a physiotherapist in 2026 that list includes:
| Cost | 2026 figure | When it lands |
|---|---|---|
| HCPC registration renewal | £246.68 for two years (£123.34 a year), or by direct debit | Physiotherapists renewed 1 February to 30 April 2026; next renewal 2028 |
| CSP chartered membership, practising in the UK | £470.04 a year (£480.84 from 2027) | From 1 January, or monthly |
| Professional indemnity | Varies by insurer and profession | Policy anniversary |
| ICO data protection fee | Per your tier | Anniversary of registration |
| Software paid annually | Varies | Anniversary |
CSP membership includes professional liability insurance for members; osteopaths, chiropractors, podiatrists, counsellors and others usually buy indemnity separately, and it can be the largest single annual payment a solo practice makes. Our guide to what insurance a practice needs covers the policies.
Either pay monthly where you can, or forecast a monthly transfer into a reserve so the annual bill is already sitting there when it lands.
Build your own forecast
The calculator below is the method in this article, filled in with the worked example that follows. Change any figure to your own: your balance, your fees, the weeks your insurers take, and the tax and renewal dates in your diary. It shows the lowest balance in the next 13 weeks, and the same quarter if it goes badly. It is also on its own page in our free tools.
A worked example
A solo physiotherapist, sole trader, renting a room. Thirteen weeks from Monday 2 November 2026 to Sunday 31 January 2027.
Assumptions: £65 a session (close to the Barometer's £63 median physiotherapy follow-up fee); a normal week of 20 self-pay and 6 insured sessions; insurers pay six weeks after the session, at the same fee for simplicity; room rent £700 a month; drawings £600 a week; running costs £90 a week; CSP membership paid annually in January; a 31 January tax bill (balancing payment plus first payment on account) of £7,500; opening balance £4,000.
| Week starting | Sessions | Self-pay in | Insurer in | Out | Net | Closing balance |
|---|---|---|---|---|---|---|
| 2 Nov | 26 | £1,300 | £390 | £1,390 | £300 | £4,300 |
| 9 Nov | 26 | £1,300 | £390 | £690 | £1,000 | £5,300 |
| 16 Nov | 26 | £1,300 | £390 | £690 | £1,000 | £6,300 |
| 23 Nov | 26 | £1,300 | £390 | £690 | £1,000 | £7,300 |
| 30 Nov | 26 | £1,300 | £390 | £1,390 | £300 | £7,600 |
| 7 Dec | 24 | £1,170 | £390 | £690 | £870 | £8,470 |
| 14 Dec | 20 | £975 | £390 | £690 | £675 | £9,145 |
| 21 Dec | 10 | £520 | £390 | £690 | £220 | £9,365 |
| 28 Dec | 4 | £195 | £390 | £1,390 | -£805 | £8,560 |
| 4 Jan | 16 | £780 | £390 | £1,160 | £10 | £8,570 |
| 11 Jan | 22 | £1,105 | £390 | £690 | £805 | £9,375 |
| 18 Jan | 25 | £1,235 | £390 | £690 | £935 | £10,310 |
| 25 Jan | 26 | £1,300 | £325 | £8,190 | -£6,565 | £3,745 |
What the forecast shows that a profit figure would not:
- Christmas looks fine in cash terms, because insurer money from October and November sessions is still arriving.
- The tax bill takes the balance below where it started. Eleven good weeks of saving are gone in one payment, and the closing balance of £3,745 is the lowest point in the quarter.
- February will be thin. Insurer receipts for the Christmas weeks arrive in the first half of February: £130, £65 and £260 in the three weeks that follow, against £390 in a normal week. And the second payment on account is due on 31 July, in the run-up to the August trough.
The fix is not complicated: a tax pot built up weekly from November, or reducing drawings in December rather than in February. The forecast is what tells you to do it in November.
How do you forecast with no trading history?
The example above uses last year's shape. A practice in its first months does not have one, which is when a forecast is most useful and hardest to build.
Three substitutions work.
Use appointments already booked, not sessions you hope to see. Your diary for the next three weeks is close to fact. Beyond that, forecast a slow climb in sessions per week and resist making the line steeper because you feel optimistic. A forecast you have talked yourself into is worse than none.
Use your own costs, which you do know. Room hire, drawings, indemnity, registration and software are all knowable to the pound on day one. Build the "money out" column properly even while "money in" is a guess, because the outgoings are what determine how long you last.
Model insurer money as arriving late and be pleased when it does not. Two months from session to payment is a cautious assumption for a practice with no payment history to measure.
For the fuller version of this calculation, including how deep the trough goes before a new practice turns the corner, see our guide to how much working capital you need before you open. It is the same arithmetic run forward from zero rather than from a trading year.
If you want a ready-made grid rather than building one, use the calculator above and download it as a spreadsheet. Start Up Loans also publishes a free cash flow forecast template on its website, and you do not have to apply for a loan to download it. Free business support lists the advisers who will sit down and go through a draft with you for nothing.
Should you forecast more than one version?
Yes, and two is enough. A single forecast tells you what happens if you are right, which is the least interesting case.
Build a base case from your diary and your history. Then copy it and build a bad case: 10% fewer sessions a week, insurers paying a fortnight slower than usual, and one annual cost arriving a month earlier than you expected. None of those is a disaster on its own. Together they are what a bad quarter actually looks like.
Then read one number from each: the lowest balance in the thirteen weeks.
| What the lowest balance tells you | |
|---|---|
| Base case stays above a month of fixed costs | Normal trading. Review weekly and carry on |
| Base case fine, bad case goes negative | You have a plan to make, not a problem to solve. Decide now which lever you would pull |
| Base case goes negative | Act this week, not next month |
The value of the bad case is not the number. It is that you decide what you would do about it while you still have options, instead of deciding in the week the money runs out. Our guide to working capital sets out the levers in order of how much they hurt.
What if you cannot pay the tax bill the forecast is pointing at?
Deal with it in November, which is what the forecast is for. But if the answer in January is genuinely that the money is not there, there is a published route and it is better than missing the payment in silence.
HMRC runs an online Self Assessment payment plan service. You have to file the tax return before you can use it, because the service works from the amount the return shows. It checks your eligibility and sets up monthly instalments if you qualify. Where you do not qualify online, HMRC's own eligibility page gives a number to call, 0300 123 1813, because a plan may still be possible by phone. Limits on the amount and the length of a plan do apply, and they change, so check them in the service rather than in an article.
Three things worth knowing before you ring.
- Interest runs on tax paid late, so an instalment plan is cheaper than doing nothing but it is not free.
- Earlier is better than later. An arrangement agreed before the deadline is a different conversation from one agreed after HMRC has started chasing.
- Free advice exists. Business Debtline, run by the Money Advice Trust, gives free confidential debt advice to self-employed people and is listed on GOV.UK among the organisations HMRC recognises.
What this is not is a planning tool. A practice that funds its tax bill through an instalment plan every year has a drawings problem rather than a cash flow problem, and the fix is the weekly tax pot in the section above.
How do I keep it up to date?
Fifteen minutes every Monday. Replace last week's forecast with what actually happened, add a new week at the end, and look at the lowest balance. If it falls below one month of fixed costs, act now: chase unpaid invoices, submit insurer claims, move a planned purchase, or adjust drawings.
The forecast gets better each week you compare it with reality. After a quarter, you will know your own insurer lag, your own seasonal shape and how much your diary utilisation drops at half term.
Where Atlacare fits
The inputs to a good forecast are in your practice software: future appointments already booked, last year's appointments by week, unpaid invoices by patient and insurer, and package balances. Atlacare holds all of those, along with insurance authorisations on the patient record and revenue reports by period. Atlacare does not build the forecast for you: use the free cash flow forecast tool above, or a spreadsheet, with those figures.
The short version
Forecast cash weekly, 13 weeks ahead, rolling. Put insurer income in the week it arrives, which is often six weeks or more after the session. Expect December and August to be your quietest months and January to be weaker than you hope, and remember that January is also when tax is due. Add every annual cost before it lands. Watch the lowest balance, not the average.
Frequently asked questions
What is a 13-week cash flow forecast?
A week-by-week table of expected receipts and payments for the next quarter, with a running bank balance. You update it weekly, dropping the past week and adding a new one at the end.
When are physiotherapy clinics quietest?
December and August, according to self-reported data from 715 UK clinic owners in the UK Private Practice Barometer 2026. January is also net negative, despite the new year.
How long does Bupa take to pay a physiotherapy invoice?
Bupa's network terms say it pays by BACS within seven days of an invoice being cleared for payment, and asks providers not to chase until 45 days after the invoice date.
How much cash should a clinic keep?
At least one month of fixed costs as a buffer, plus a separate tax reserve. Three months of fixed costs is comfortable for a practice exposed to insurer payment lag or strong seasonality.
What happens if I cannot pay my Self Assessment bill in January?
HMRC runs an online payment plan service for Self Assessment, which requires the tax return to be filed first and checks eligibility before setting up instalments. Where the online route does not apply, HMRC's eligibility page gives a number to call. Interest still accrues on tax paid late.
Is there a free cash flow forecast template?
Yes. Start Up Loans publishes a free cash flow forecast template, and downloading it does not commit you to a loan application. Business Gateway, Business Wales and English Growth Hubs also run free workshops on completing one.
How do I forecast cash flow in a brand new practice?
Forecast money out from known costs, which you can price exactly, and money in from appointments already booked plus a deliberately slow climb beyond them. Assume insurer payments take about two months until you have your own data to measure.
General information, not financial advice. Seasonality figures are self-reported survey data. The worked example is illustrative and its figures are invented for clarity apart from the cited fees. Correct at 2 October 2026.
Sources: HMDG, UK Private Practice Barometer 2026: seasonality · Bupa, Terms and conditions for delivering physiotherapy to Bupa members · HCPC, Paying renewal fees · CSP, 2026 membership subscription · GOV.UK, Payments on account · GOV.UK, if you cannot pay your tax bill on time · GOV.UK, set up a Self Assessment payment plan · GOV.UK, voluntary and community sector organisations who can give you extra support · Start Up Loans, how to apply
Related: How much should I pay myself? · How to read your own practice accounts · What is good diary utilisation? · Which six numbers should a clinic owner track?
