Locum Dentist vs Associate: How Does the Tax Treatment Differ in 2026/27?

Locum Dentist vs Associate: Which Role Suits Your Tax Position?

For UK dentists, the choice between working as a locum or as an associate is not only about daily rates and flexibility. The tax and employment-status treatment of each role differs in several important ways, affecting your net income, allowable expenses, pension accrual and exposure to the off-payroll working rules.

This article compares the treatment of a locum dentist and an associate for the 2026/27 tax year. We use a worked example to show how each role is taxed, what you can claim, and where the risks sit. The figures are drawn from current HMRC rules, NHS pension regulations, and the off-payroll working (IR35) legislation in force since 6 April 2021.

Tax Status: Self-Employed or Employee?

Associates

Most dental associates in the UK are treated as self-employed for tax purposes, and that remains the norm even under a BDA model associate agreement. The crucial point is that status turns on the substance of the working arrangement, not the contract label. HMRC and the tax tribunals weigh the established factors: control (does the principal direct when and how you work?), personal service and the right to send a substitute, mutuality of obligation, financial risk (do you bear materials or lab costs?), and how far you are integrated into the practice. None is decisive on its own; the overall picture governs.

The dental model usually points to self-employment because associates retain clinical autonomy, carry their own indemnity and equipment, and are paid on a fee split. But a rostered, practice-supplied, no-autonomy arrangement carries real status risk, and HMRC could argue the relationship is in truth employment, with PAYE and employer NIC due. The BDA model contract is supportive evidence, not a guarantee. For the factors in more depth, see our associate vs self-employed status guide and when HMRC may challenge associate self-employment. There is also a full Associate Tax Survival Guide.

Locum Dentists

Locum dentists are typically self-employed as well. You work on a short-term basis, often across several practices, set your own schedule, and bear your own indemnity, CPD and equipment costs. The control and integration tests usually point more clearly to independence than they do for a tied associate, so the self-employment position is generally cleaner.

The complication arises where a locum trades through a personal service company (PSC). That brings the off-payroll working rules into play, and these now sit with the engaging client rather than the locum. We deal with who decides, and what an SDS is, in the IR35 section below. For the structural comparison between trading personally and through a company, see locum dentist limited company vs self-employed, and our locum dentist tax services page.

Income Tax and National Insurance: A Worked Example

Let us compare two dentists, each with £80,000 of gross income in 2026/27. One works as a self-employed associate; the other works as a locum through a company on an engagement that has been determined outside IR35, so the company receives the full fee. We assume no other income and that the £12,570 personal allowance applies in full. Figures are illustrative and rounded.

Associate (Self-Employed), 2026/27

• Gross income: £80,000
• Allowable expenses: £5,000 (indemnity, CPD, lab fees, travel, professional subscriptions)
• Net profit: £75,000
• Income tax: 20% on £37,700 (£12,571 to £50,270) = £7,540, plus 40% on £24,730 (£50,271 to £75,000) = £9,892. Total income tax = £17,432.
• Class 4 NIC: 6% on £37,700 (£12,571 to £50,270) = £2,262, plus 2% on £24,730 above £50,270 = £494. Total Class 4 NIC = £2,756. There is no separate weekly Class 2 charge: from 6 April 2024 a self-employed dentist with profits above the small profits threshold is treated as having paid Class 2 and keeps the state-pension credit at no cost.
• Total tax and NIC: £20,188.
• Net income after tax: £59,812.

Locum (Company, Outside IR35), 2026/27

• Gross fee to the company: £80,000
• Company expenses: £5,000 (indemnity, CPD, travel, accountancy, software)
• Profit before tax: £75,000
• Corporation tax: 19% small-profits rate on the first £50,000 = £9,500, plus 25% on £25,000 = £6,250 (marginal relief tapers the rate between £50,000 and £250,000; the £19,000-plus combined figure here is a simplified two-band illustration). Total corporation tax = £15,750.
• Profit after corporation tax: £59,250, all assumed taken as a dividend.
• Dividend tax (2026/27 rates, Finance Act 2026 section 4): £500 dividend allowance, then ordinary rate 10.75% on £37,700 = £4,053, then upper rate 35.75% on the £21,050 falling above the basic-rate band = £7,525. Total dividend tax = £11,578.
• Total tax (corporation tax plus dividend tax): £27,328.
• Net income after all tax: £47,672.

On these assumptions the associate keeps about £59,812 after tax, while the outside-IR35 company locum keeps about £47,672, a gap of roughly £12,140. The associate pays only income tax and Class 4 NIC; the locum pays corporation tax and then dividend tax on the extracted profit. The 6 April 2026 increase in dividend rates (ordinary 8.75% to 10.75%, upper 33.75% to 35.75%) widened this gap compared with 2025/26. The company route can still appeal where the locum retains profit for reinvestment, smooths income across years, or genuinely employs a spouse at a market rate. The point is that the treatment differs materially, so the structure has to be modelled on your own numbers, not assumed.

Allowable Expenses: What Can Each Claim?

Associates

As a self-employed associate you can claim costs incurred wholly and exclusively for your dental work. Common claims include:

• Professional indemnity (Dental Protection, MDU, MDDUS)
• CPD course fees, travel and accommodation genuinely relevant to current practice
• GDC annual retention fee (note the GDC restoration fee and any penalty fees are not allowable)
• Professional subscriptions on HMRC's approved List 3 (BDA, specialty bodies, dental journals)
• Surgery rent where you pay a fixed charge to the practice
• Lab fees and materials where you bear the cost
• Loupes and instruments (usually relieved through capital allowances or the Annual Investment Allowance)
• Travel between practices (but home to a single regular practice is non-deductible commuting)
• A reasonable apportionment of home-office, phone and internet costs for genuine business use
• Accountancy fees

You cannot claim your own dental treatment or personal items. For the wider picture, see our associate tax page.

Locum Dentists

Locums claim a similar set of costs, with two practical differences. Because you work at multiple sites, travel between practices is more readily allowable, and if your home is genuinely your business base, home-to-practice travel can qualify too. A locum can also claim:

• Professional indemnity and public liability cover
• CPD costs relevant to current practice
• GDC retention fee and List 3 subscriptions
• Equipment and instruments you buy
• Accountancy and bookkeeping fees
• If you trade through a company, employer pension contributions, which are deductible for corporation tax on a paid basis and carry no NIC, subject to the pension annual allowance

Where an engagement is inside IR35, the deemed-employment calculation strips out most of these reliefs: broadly a flat 5% allowance of the relevant fee is no longer available for engagements where the client makes the determination, so the company is left only with limited statutory deductions and any travel or subsistence that would be allowable for an employee. That restriction is a major reason the company wrapper loses its appeal once an engagement falls inside IR35.

NHS Pension Implications

Associates

A self-employed associate doing NHS work can be a practitioner member of the NHS Pension Scheme, provided they are on a Performers List and hold the relevant NHS contract link. Pensionable earnings are based on NHS-derived income, not private fees, and you pay tiered member contributions (ranging from 5.2% to 12.5% of pensionable pay depending on the band). The employer contribution is met centrally for the NHS work rather than by the practice principal, so the associate is not out of pocket for it.

This is a valuable benefit and a key reason many associates keep meaningful NHS commitment. For the mechanics, see our NHS Pension Scheme Essentials guide.

Locum Dentists

Locums doing NHS work can also pension that income as practitioner members, but the administration is different. You apply to join, complete locum forms for each engagement, and your pensionable pay is based on the NHS fees you earn. Many self-employed locums carry the burden of the employer contribution in their own pricing because they are not engaged through a host practice in the usual way, and the employer rate is now 23.7% of pensionable pay (23.78% including the administration levy) from 1 April 2024, up from the previous 20.6%. Build that cost into your day rate if you want NHS accrual.

If you trade through a company, employer pension contributions paid by the company are deductible for corporation tax, but a company cannot pension NHS-derived income into the NHS scheme in the way a practitioner can: NHS pensionability follows the practitioner, and dividends are never pensionable. Anyone weighing incorporation should model the pension accrual they would lose, not just the headline tax position.

IR35 and Off-Payroll Working: Who Decides for a Company Locum?

The biggest tax risk for a locum trading through a company is the off-payroll working regime. The key change locums sometimes still get wrong is who makes the decision. Since 6 April 2021, where the engaging client is medium or large (most NHS practices and corporate dental groups are), the client, not your company, determines your IR35 status. The client must issue a Status Determination Statement (SDS) setting out the outcome and the reasons for it, and must take reasonable care in reaching it. These rules sit in Chapter 10, Part 2 of ITEPA 2003.

If you are determined inside IR35, the fee-payer deducts PAYE and employee NIC before paying your company, and accounts for employer NIC at 15% on earnings above the £5,000 secondary threshold (the rate and threshold that have applied since 6 April 2025). The company receives the income net, and the usual salary-plus-dividend extraction is not available on that money, so the wrapper earns little. If you disagree with an inside determination, there is a client-led disagreement process and you have 45 days to make your case; the client must respond with its decision and reasons.

Only where the client is genuinely small does responsibility revert to your own company under the original intermediaries rules. A client is small where it does not exceed at least two of three limits: turnover not more than £15 million, balance sheet total not more than £7.5 million, and no more than 50 employees (the financial limits were raised from £10.2 million and £5.1 million from 6 April 2025). A single-handed or small practice may well fall under those limits; a corporate group will not, which is why locums working for large groups so often find an inside-IR35 determination waiting for them. A locum across several practices may hold a mix of inside and outside determinations at once.

For the detail on NHS engagements specifically, see how IR35 affects locum dentists on NHS engagements. Associates rarely need to worry about off-payroll because they are not usually incorporated, but the parallel rules for incorporated associates are covered in IR35 for dental associates. Our page for locum dentists sets out how to manage the risk in practice.

Which Role Is More Tax-Efficient?

There is no universal answer. It turns on your income level, your expenses, your pension goals, and whether your engagements fall inside or outside IR35.

• For most associates, self-employment is straightforward and efficient. You pay income tax and Class 4 NIC, claim genuine expenses, and access NHS practitioner pension accrual on NHS work with the employer contribution met centrally rather than from your pocket.
• For locums outside IR35, a company can offer flexibility, especially where you retain profit for reinvestment or genuinely employ a spouse at a market rate. But the combined corporation tax and dividend tax bill can exceed self-employment tax, and the gap widened with the 6 April 2026 dividend-rate rise.
• For locums inside IR35, the company wrapper achieves little: the fee-payer deducts PAYE and NIC at source and the deemed-employment rules strip out most reliefs, so you are often better off as a self-employed locum or as an employee, with far less administration.

If you are considering a change of role, model the numbers on your own figures, including the NHS pension accrual at stake, before you commit. Our team at Dental Finance Partners can run that comparison for you. Contact us to talk it through.