For a self-employed associate dentist, knowing exactly which costs are allowable against your income is one of the most reliable ways to keep your tax bill in proportion. Claim the right items, with records to back them up, and you only pay tax on your real profit. Claim the wrong ones, or claim with no evidence, and you invite an HMRC enquiry.
This is the expenses hub for associate dentists. It sets out what is and is not allowable, with the nuances that trip people up most often: the GDC retention fee being allowable while restoration fees are not, the line between revenue CPD and capital "new skill" training, and the route for claiming loupes through capital allowances rather than as a straight expense. It is written for self-employed associates on a contract for services, not salaried associates taxed through PAYE. If you are unsure which you are, start with our associate dentist tax guide.
The one test behind every claim: wholly and exclusively
Every allowable expense for a self-employed associate has to pass a single statutory test. The cost must be incurred wholly and exclusively for the purposes of your dental trade (ITTOIA 2005 s.34). If a cost is incurred entirely for the business, it is allowable. If it has a private element, you cannot claim the whole thing: you apportion it and claim only the business proportion. If there is no realistic way to separate the business part from the private part, the whole cost can fail.
That single rule explains almost every decision below. Indemnity is allowable because you cannot practise without it. A gym membership is not, because it benefits you personally. A laptop used for both patient records and family streaming is apportioned. Hold the "wholly and exclusively" question in mind and most expense decisions answer themselves.
Allowable versus not: the quick reference
The table below summarises the core categories for an associate dentist. The detail and the exceptions follow underneath, so read the relevant section before relying on a one-word answer.
| Cost | Allowable? | How it is treated |
|---|---|---|
| Professional indemnity (Dental Protection, MDU, MDDUS) | Yes | Revenue expense, in full |
| GDC annual retention fee | Yes | Revenue expense, in full |
| GDC restoration fee / CPD-shortfall penalty | No | Arises from non-compliance, not the trade |
| List 3 subscriptions (BDA, FGDP, specialty bodies, dental journals) | Yes | Revenue expense if the body is on HMRC's List 3 and relevant to your work |
| CPD maintaining current skills | Yes | Revenue expense (course, conference, travel to attend) |
| CPD creating a genuinely new skill or qualification | Often no | Can be capital, not a revenue deduction |
| Loupes, handpieces, clinical instruments | Yes | Capital allowances, usually full relief under AIA |
| Consumables (gloves, masks, impression materials) | Yes | Revenue expense, in full |
| Mileage between practices on the same day | Yes | Approved mileage rates (see below) |
| Home to main practice (and back) | No | Ordinary commuting, never allowable |
| Use of home for practice admin | Yes | Simplified flat rate or actual-cost apportionment |
| Phone and internet | Partly | Apportioned to the business-use proportion |
| Accountancy fees | Yes | Revenue expense, in full |
| Business bank charges and business-loan interest | Yes | Revenue expense, in full |
| Fines, penalties, parking and speeding tickets | No | Never allowable |
| Ordinary clothing, even if worn only at work | No | Only protective or branded clinical wear qualifies |
Professional indemnity, the GDC fee and the restoration trap
Two costs are non-negotiable for any practising associate, and both are allowable in full. The first is professional indemnity through your dental defence organisation (Dental Protection, MDU or MDDUS). You cannot treat patients without it, so it is wholly and exclusively for the trade. If you are a genuine employee rather than self-employed, check whether your employer arranges cover, because you cannot claim a cost someone else has paid.
The second is the GDC annual retention fee. GDC registration is a condition of practising as a dentist, so the annual retention fee is allowable. Specialist-register fees are allowable on the same basis where the specialty is relevant to your work.
Here is the nuance that catches associates out. The annual retention fee is allowable, but a GDC restoration fee (the higher fee you pay to get back onto the register after letting it lapse or being removed) is not allowable. Nor is any CPD-shortfall penalty. These do not arise from carrying on your trade. They arise from a failure to comply, which HMRC treats as personal rather than a cost of the business. So claim the retention fee every year, but leave any restoration fee or penalty off your return.
Professional subscriptions and the List 3 rule
Subscriptions to professional bodies and learned societies are allowable, but only where the body appears on HMRC's approved List 3 and is relevant to your work as a dentist. The British Dental Association, the Faculty of General Dental Practice, the relevant specialty societies and subscriptions to recognised dental journals are the typical claims. If a body is not on List 3, the subscription is not deductible even if membership feels essential. List 3 is published and updated by HMRC, so it is worth checking your bodies are on it.
The test is genuine relevance. A subscription that helps you do your current dental work passes. A general-interest membership with no professional bearing does not.
CPD: where revenue ends and capital begins
Continuing Professional Development is a General Dental Council requirement, and most of it is allowable. The cost of courses, conferences, webinars, and the travel and any necessary accommodation to attend them are deductible when the training maintains or updates a skill you already use in your current practice. Clinical updates, refreshers, communication and practice-management CPD all sit comfortably here.
The line to watch is between maintaining existing skills and acquiring a genuinely new one. Training that simply keeps your existing competence current is a revenue expense. Training that gives you a genuinely new skill or qualification, one that lets you offer a treatment or service you could not provide before, can be treated as capital rather than revenue, because it creates a lasting new asset (your expanded capability) rather than maintaining the trade you already carry on. Capital training of that kind may not be deductible against your associate income. The classification is fact-specific, so keep the course outline and a short note of why the training relates to your existing work. Our deep dive on whether CPD courses are tax deductible walks through the revenue-versus-capital boundary in detail.
Loupes and instruments: capital allowances, not a straight expense
Associates routinely buy their own loupes, handpieces and clinical instruments. These are capital items, not day-to-day running costs, so the relief comes through capital allowances rather than as a normal expense line.
In practice the route is the Annual Investment Allowance (AIA), which gives full relief in the year of purchase on qualifying plant and machinery up to the £1,000,000 AIA limit. That covers loupes, instruments, and equipment such as autoclaves, compressors and computers used for the practice. It does not cover cars, which sit under a separate capital-allowance regime. The condition is that the equipment is used wholly for your dental business. If there is private use, you apportion and claim only the business proportion.
By contrast, consumables such as gloves, masks, impression materials and laboratory items are revenue expenses, claimed in full in the year you incur them. The mental model is simple: something you use up quickly is a revenue expense, while something durable that you keep and use over years is a capital item claimed through allowances. Keep invoices for both.
Travel and mileage: the commuting trap
Travel is the most-claimed associate expense and the most frequently challenged, because the rules are not intuitive. The decisive question is where you are travelling from and to.
Travel between your home and your main place of work is ordinary commuting. It is never allowable, no matter how far you live from the practice. If you work at a single practice, you generally have no claimable travel at all. Where it gets useful is multiple practices: a journey from Practice A to Practice B on the same working day is a deductible business journey. The first leg of the day from home to the first practice, and the last leg home, remain commuting and stay non-deductible. Travel from a practice to a CPD course or a professional meeting is also allowable.
You claim car and van mileage using HMRC's approved mileage rates rather than tracking actual running costs. For the 2026/27 tax year these rates increased: cars and vans are now 55p per mile for the first 10,000 business miles in the tax year, then 25p per mile above that (for 2025/26 and earlier the first-10,000 rate was 45p, with 25p thereafter unchanged). Motorcycles are 24p per mile and bicycles 20p, both unchanged. You use these flat rates instead of actual fuel, servicing, insurance and depreciation. You cannot mix the two methods for the same vehicle.
Whichever rate applies, keep a mileage log: date, start and end point, purpose of the journey, and miles. Without it HMRC can reject the whole travel claim. A simple spreadsheet or a tracking app is enough. The mechanics for associates working across several sites are covered in full in our guide on whether associate dentists can claim mileage at multiple practices.
Use of home, phone and internet
If you do genuine practice administration from home (booking, patient notes, CPD reading, correspondence), you can claim for that business use. There are two routes. The simplified flat rate gives a set monthly amount based on the hours you work from home each month, with no need to itemise bills. The actual-cost method apportions your real household running costs (heating, lighting, and so on) by the proportion of your home and time used for business, and needs more detailed records. For most associates the flat rate is simpler and adequate.
What you cannot do as an associate is claim mortgage interest, rent or council tax as a use-of-home cost. Those relate to your home as a whole, not to a specific business use, and HMRC is firm on the point.
Phone and internet follow the apportionment principle. If you use a personal phone and broadband partly for the practice, claim only the business-use proportion and be ready to justify the split. A line used solely for the business is claimable in full.
Accountancy, bank charges and loan interest
Fees for preparing your accounts and tax return are an allowable expense, and the cost of getting your tax right is usually money well spent. Business bank charges on an account used for the practice, and interest on a genuine business loan (for example, finance taken out to buy clinical equipment), are also allowable revenue costs. As always, the borrowing or the account has to relate to the trade, not to private spending.
Clothing, and what you can never claim
Clinical scrubs, tunics and protective footwear are allowable when they are specific to the role and not suitable for everyday wear. A branded uniform carrying the practice name is clearly business-specific and allowable. Ordinary clothing is not allowable even if you only ever wear it at work, because it also meets the everyday need to be clothed. That is the line HMRC draws between protective or branded clinical wear (allowable) and ordinary clothing (not).
Some costs are simply never allowable for a self-employed associate:
- Fines and penalties, including parking tickets, speeding fines and HMRC late-filing penalties
- GDC restoration fees and CPD-shortfall penalties (the retention fee is fine, these are not)
- Childcare, even when you work late or attend evening CPD
- Gym membership and personal health insurance, unless contractually provided
- Entertainment and ordinary day-to-day meals (subsistence may be claimable only when you are genuinely away overnight on business)
- Capital items used wholly privately, such as a family car
National Insurance: what changed for the self-employed
One point on National Insurance saves associates from a common error. Class 2 NIC liability was removed from 6 April 2024. If your profits are at or above the small-profits threshold you are treated as having paid Class 2 and keep your state-pension entitlement, with nothing to pay. You do not need to budget a weekly Class 2 charge. Class 4 NIC still applies on profits: 6% between £12,570 and £50,270, then 2% above £50,270 (2025/26 thresholds). Your allowable expenses reduce the profit that both income tax and Class 4 are charged on, which is exactly why getting them right matters.
Records: the part HMRC actually checks
HMRC can open an enquiry into your return and ask for evidence of any expense. The standard is adequate records. For most associates that means:
- Invoices and receipts for your purchases
- A mileage log for business journeys
- Bank statements showing payments to suppliers and the practice
- Practice statements showing your fee split and any deductions made at source
- Course outlines and attendance records for CPD
Digital records are fine, and from 6 April 2026 Making Tax Digital for Income Tax makes them effectively compulsory for sole traders with qualifying income over £50,000, which is most full-time associates. Quarterly digital updates replace the once-a-year scramble, so moving to accounting software now is the sensible step. Without records, HMRC can disallow claims and charge the tax due plus interest and penalties, so good record keeping is your best defence.
Where this fits
Getting associate expenses right is about applying the wholly-and-exclusively test honestly and keeping the evidence, not about pushing the boundaries. HMRC pays particular attention to healthcare professionals, and dental associates are a known area of focus, so the steady, well-documented approach is also the safest one.
For the wider picture, including Self Assessment, payments on account and how your expenses feed into your overall tax position, see our associate dentist tax guide. If you are unsure whether a specific cost is allowable, or HMRC has opened an enquiry, speak to a dental-specialist accountant before you claim. You can also book a free practice health check with our team to review your expenses against your working pattern.