A mixed NHS and private dental practice looks like one business, but for accounting it behaves like two, and the two could hardly behave less alike. On one side, NHS income arrives as smooth monthly contract payments that must be reconciled against delivery at year-end, with clawback or carry-forward hanging over the figure. On the other, private income arrives treatment by treatment, varying with patient flow and plan arrangements. Bolt on a VAT position that can differ between exempt dental care and standard-rated cosmetic work, and a cost base that has to be split fairly between the two, and you have a set of accounts where the easy mistakes are expensive ones.

This guide is about getting that accounting right. We cover how to recognise each income stream correctly, the patient-charges trap that quietly distorts so many dental accounts, the VAT partial-exemption question, and how to split costs so your management accounts show the real profitability of each side. Done well, a mixed practice's accounts become a clear management tool; done carelessly, they overstate profit, misstate tax and hide which half of the practice actually pays.

Why a mixed practice is harder to account for

The core difficulty is that the two income streams have different shapes. NHS income is smooth and contractual but provisional, subject to a year-end true-up. Private income is lumpy and immediate but unsmoothed. They are recognised on different bases, they carry different VAT treatments, and they draw on a shared cost base that has to be divided. Each is straightforward in isolation; the work is in keeping them straight together and producing accounts that reflect both the combined statutory picture and the split management view. A practice that treats its accounts as one undifferentiated pot loses the ability to manage either side well.

NHS income: smooth monthly payments plus reconciliation

NHS contract payments are recognised as income through the year, in line with the even monthly payments you receive. But that figure is provisional until the year-end reconciliation. If your delivery is heading below 96% of target, you will face a clawback, and an expected clawback should be provided for as a liability that reduces recognised income, so you do not book money you are going to repay. An under-delivery of 4% or less is a carry-forward, which is a next-year delivery obligation rather than a cash clawback and so is treated as a disclosure and planning matter, not a balance-sheet provision. Our guide to UDA carry-forward and clawback rules sets out the distinction, and our guide to accounting for NHS contract payments covers the recognition mechanics in full. The single most important habit is to adjust the headline contract income for the reconciliation, not to take the monthly payments at face value.

The patient-charges trap

Here is the error that distorts more dental accounts than any other: treating NHS patient charges as income on top of the contract value. They are not. When a patient pays a Band 1, 2 or 3 charge, that money goes towards the contract income you would have received anyway, not in addition to it. The contract value already assumes a level of patient-charge income within it. Count the charges separately and add them to the contract value and you double-count, overstating income and profit and, in turn, tax. This trap is so common precisely because the charges feel like cash the patient hands over, which intuitively looks like extra revenue. It is not. Build the accounts so patient charges are recognised as part of the contract value, never as a bolt-on, and the distortion disappears.

Why provisioning for clawback protects you

It is worth being concrete about why the clawback provision matters so much, because it is the adjustment most likely to be skipped and the one with the sharpest consequences. Imagine a practice that recognises its full £15,000 monthly NHS payment as income all year, reaching £180,000 of recognised NHS income, but which has delivered only 92% of its target. At reconciliation, the commissioner recovers the overpayment for the undelivered activity. If no provision was made, the accounts showed £180,000 of NHS income and a profit calculated on it; the practice has paid tax on that profit; and now it must repay cash it has already been taxed on. The correction is messy and the cash-flow hit is doubled.

With a provision, the picture is honest from the start. At the year-end, the expected clawback is estimated and booked as a liability that reduces recognised NHS income to the level actually earned, say £165,600 rather than £180,000. Profit falls accordingly, the tax is calculated on the real figure, and when the commissioner recovers the cash it simply settles a liability already on the balance sheet, with no nasty surprise to profit or tax. This is the difference between accounts that anticipate reality and accounts that are ambushed by it, and it is why a mixed practice should never take its headline NHS income at face value.

Private income: treatment by treatment

Private fee income follows a different logic. It is generally recognised when the treatment is provided and the fee is earned, treatment by treatment, rather than smoothed across the year. Where patients pay through a plan, income is typically recognised as the service is delivered across the plan period. Deposits and advance payments for treatment not yet carried out are deferred income until the work is done. The defining feature is that private income tracks the actual delivery of treatment and the timing of payment, not a fixed monthly schedule. This makes private income more volatile month to month, which is one reason a growing private share changes the cash-flow profile of a practice, as covered in our guide to going private.

Plan income and how it is recognised

Many mixed practices run a patient plan on the private side, where patients pay a regular monthly amount in exchange for a defined set of care, and plans have their own recognition logic worth getting right. The monthly plan payments are typically recognised as income as the service is delivered across the plan period, matching the income to the care provided rather than booking it all when the cash arrives. Where a plan is administered by a third party that collects the payments and remits them to the practice, the accounting needs to reflect the net position and any administration fee, and to separate the practice's earned income from money simply passing through. Done properly, plan income smooths the private side of the practice and makes it more predictable, which is one of its attractions, but the smoothing in the accounts must follow delivery, not just collection, so that a year of strong plan recruitment does not overstate income for care not yet given. Treating plan income with the same delivery-based discipline applied to the rest of the private stream keeps the whole private side honest.

VAT: the partial-exemption question

VAT is where a mixed practice can quietly go wrong. Dental care that is medical in purpose is VAT-exempt, whether NHS or private, so the bulk of a practice's work usually generates no VAT. But purely cosmetic work with no therapeutic purpose, some facial aesthetics, tooth whitening, can be standard-rated. A practice with both exempt and taxable supplies is partially exempt: it recovers only the input VAT attributable to its taxable work, subject to the de minimis limits, and must register if its taxable income exceeds the threshold. So the VAT questions for a mixed practice are whether any of its work is taxable, whether taxable income has reached the registration threshold, and how much input VAT it can recover. None of this is exotic, but it has to be monitored as the private and cosmetic share grows, because crossing the threshold unnoticed creates a compliance problem.

Splitting costs between NHS and private

The two income streams share a cost base, and how you split it shapes both your management accounts and your VAT recovery. Costs that relate clearly to one stream, a piece of equipment used only for cosmetic work, say, are allocated directly. Shared costs, premises, reception, general overhead, are apportioned on a sensible, consistent basis such as the share of chair time or income each stream represents. The split matters in two places. In management accounts, it reveals the true profitability of each side. In VAT, input tax on costs feeding taxable cosmetic work may be recoverable while input tax on exempt work is not, so the apportionment feeds the partial-exemption calculation. A defensible, consistent method, agreed with your accountant, is what keeps both the management view and the VAT position sound.

The VAT registration threshold in a mixed practice

One VAT point deserves its own treatment because it catches growing practices out. The registration threshold is tested against your taxable turnover, the standard-rated cosmetic work, not your total income, and crucially not your exempt dental care. So a practice with a large exempt NHS and private dentistry income but only modest cosmetic work may stay below the threshold for a long time, then cross it quietly as facial aesthetics or whitening grow. Because the exempt income is so much larger, an owner watching total turnover would assume they passed the threshold years ago and may not realise the taxable slice has only just reached it. The discipline is to track taxable income separately and monitor it against the threshold on a rolling basis, so registration happens on time rather than late with penalties. Once registered, the practice operates partial exemption, recovering input VAT on its taxable activity subject to the de minimis limits, and completes an annual adjustment. This is exactly the kind of moving target that a clear NHS, exempt-private and taxable-private income split makes visible, and that a single blended income figure conceals.

Where the patient-charges trap does real damage

It is worth returning to the patient-charges trap to show how it propagates if uncaught, because its effects ripple beyond a single wrong line. If a practice adds NHS patient charges to its contract value as extra income, it overstates revenue, which overstates profit, which overstates tax. But the damage does not stop there. Overstated NHS income distorts the NHS-versus-private split, making the NHS side look more profitable than it is, which can drive a bad strategic decision, expanding NHS work that is actually thinner than the numbers suggest. It can distort a practice valuation if the inflated income feeds a sale model. And it muddies the cost-allocation exercise, because the NHS side appears to carry more income to set costs against. One conceptual error, treating charges as on-top rather than towards, therefore corrupts revenue, profit, tax, strategy and valuation together. Building the bookkeeping so patient charges are always recognised within the contract value, never bolted on, closes off the whole chain of distortion at source.

Management accounts for a mixed practice

The reason all of this is worth the effort is that a single blended figure tells you almost nothing about how to run the practice. Without separating NHS and private performance, you cannot see whether the private side is subsidising a thin NHS contract, or whether the NHS contract is the stable base that lets the private side grow. Management accounts that split the two streams, with costs allocated honestly, turn a confusing combined picture into a clear view of where profit actually comes from, which in turn informs decisions about mix, capacity, recruitment and whether to expand one side or wind down another. This is the practical payoff of careful mixed-income accounting.

Cash flow in a mixed practice

The two income streams do not just look different in the accounts; they arrive differently in the bank, and managing that combined cash flow is its own discipline. NHS income is the steady heartbeat: the same monthly amount, predictable to the day, easy to budget around. Private income is the variable layer on top, rising and falling with patient flow, seasonality, the success of a treatment plan, and the timing of larger cases. A practice that leans heavily on the steady NHS payment to cover its fixed costs, and treats the private income as the variable margin, tends to manage cash comfortably. One that has come to depend on a strong run of private work to meet its commitments is more exposed when private income dips, because the fixed costs do not dip with it.

The accounting feeds this directly. Because NHS income is provisional until reconciliation, a practice that has been spending the full monthly payment while heading for a clawback is also building a future cash outflow it may not have reserved for. So good mixed-practice cash management means treating the NHS monthly payment as partly earned and partly advanced, keeping a reserve against a possible clawback, and recognising private income only as treatment is actually delivered so that deferred deposits are not mistaken for spendable cash. The same recognition discipline that keeps the accounts honest also keeps the cash flow safe.

One underrated benefit of keeping the streams cleanly separated is that it makes year-on-year comparison meaningful. If NHS and private income are blended into a single line, a shift in the mix, more private, less NHS, or vice versa, is invisible, and an owner cannot tell whether a change in total income reflects a growing private base, a shrinking NHS delivery, a clawback, or simply a fee change. Split the streams and the trend in each becomes legible: you can see private income compounding as the practice builds its plan base, NHS income flat by design, and the effect of any reconciliation in the year it occurred. That legibility is what turns a year-end set of accounts from a backward-looking record into a forward-looking management signal, telling you which part of the practice is growing and which is static, and informing where to invest next.

A worked month

Take a single month in a mixed practice with around £30,000 of income.

  • NHS: a £15,000 monthly contract payment is recognised as income, but flagged as provisional pending reconciliation. Patient charges collected on NHS treatments are recognised within that contract value, not added to it.
  • Private exempt: £12,000 of ordinary private dentistry (examinations, restorations, hygiene), recognised as the treatments are delivered, VAT-exempt.
  • Private cosmetic: £3,000 of purely cosmetic work that is standard-rated, which counts towards the VAT registration threshold and, if the practice is registered, carries output VAT, with related input VAT recoverable.

From one month's takings, three different recognition and VAT treatments. Blend them into a single income line and you lose the reconciliation provision, you risk double-counting patient charges, and you bury the taxable cosmetic income that drives your VAT position. Separate them and every figure stays honest.

Systems and bookkeeping for a mixed practice

Good mixed-income accounting is far easier when the systems support it from the start, rather than being reconstructed at year-end. The practice management software usually captures NHS activity and private treatment separately at source, and the bookkeeping should mirror that split: separate income codes for NHS contract income, private exempt dentistry and private standard-rated cosmetic work, with patient charges mapped within the NHS contract value rather than to a separate revenue line. Costs should be coded so that directly attributable items go to the right stream and shared items are flagged for apportionment. With this structure in place, producing both the combined statutory accounts and the split management view is a matter of running reports, not untangling a blended ledger.

The discipline pays off at three moments: at each VAT return, where the taxable income and recoverable input VAT are already identified; at the year-end, where the clawback provision, deferred private income and partial-exemption adjustment slot into a clean structure; and whenever the owner wants a management read on how each side is performing. A practice that invests a little in getting the chart of accounts and the coding right at the outset saves itself the recurring cost and risk of pulling the streams apart after the fact, and gains a reliable, real-time view of a business that is genuinely two businesses under one roof.

Getting the year-end right

The year-end pulls the threads together: provide for any expected NHS clawback so profit is not overstated, treat a carry-forward as a next-year obligation, recognise private income to the point treatment was actually delivered, defer any advance payments, complete the VAT partial-exemption calculation and annual adjustment if registered, and present management figures that show NHS and private performance separately. Each of these is a place a generalist can slip, which is why a specialist dental accountant is worth having for a mixed practice. Our guide to the complete private-practice tax position and our existing notes on the NHS and private mix in dental accounts sit alongside this one.

The financial KPIs that flow from well-kept mixed accounts, income per surgery, profit by stream, the cost per UDA against private fee yield, are what let an owner steer the practice rather than just record it. We cover those in our guide to the pensionable pay calculation on the NHS side and in the practice-finance guides that build on this accounting foundation. Get the two income streams recognised correctly, avoid the patient-charges trap, keep the VAT position monitored and split the costs honestly, and a mixed practice's accounts stop being a source of confusion and start being the clearest tool you have for running the business.