If you split your week across two or three practices, cover locum shifts, or run a domiciliary list visiting patients at home, your travel bill is real money. So is the cost of doing your admin, CPD and treatment planning from a study at home.
The frustrating part is that not all of it is claimable, and the rules turn on small details: where your "base" is, whether a practice counts as temporary, and which method you use to work the numbers out.
This guide is for self-employed dentists, including associates and dental locums. We'll cover what mileage you can actually claim, the commute trap that catches people every year, how the 45p rate works, and how to claim use of home without overstating it. There's a worked example with current figures and a quick decision walkthrough at the end.
If you operate through your own limited company, some of the detail differs, and we flag that as we go.
Can a dentist claim mileage for driving between practices?
Yes. Travel between two separate places of work in the same day is business travel, so if you finish a morning list at one practice and drive to a second practice for the afternoon, that journey is allowable.
The same applies to a genuinely mobile or domiciliary dentist who travels from a base to a series of patients or sites. The cost of getting from one work location to another, or out to a temporary site, is a normal business expense.
What you generally cannot claim is the journey from home to a regular base, and that is where most claims go wrong. The next section explains why.
Why is the commute to your practice not allowable?
The long-standing principle for the self-employed is that travel from home to a fixed base, the place you regularly work from, is not an expense of the trade. HMRC's Business Income Manual draws this directly from the case of Horton v Young, which separated two kinds of trader: one who travels from home to a settled base like a shop, office or surgery, and an "itinerant" trader who travels from home to a number of different locations for the temporary purpose of completing a job at each.
For the first type, the home-to-base trip is ordinary commuting and is disallowed. For the second, the travel can be allowable because there is no single regular base, the home is effectively the base of operations.
In practice, most associates working a fixed pattern at one or two practices have a base, or two bases, rather than being itinerant. So the morning drive from home to your usual Monday practice is a commute, not a business trip. The drive from that practice to a second practice later the same day is business travel.
A genuinely mobile dentist, with no regular practice base and a home that is the operational centre of the work, is in a different position and can have a much stronger claim for travel from home to patients. The facts decide it, so keep evidence of how you actually work.
How does the 45p mileage rate work?
If you use your own car or van, the simplest way to claim is HMRC's flat mileage rate, known as simplified expenses for the self-employed. You multiply your business miles by a set rate and claim that figure, instead of working out the actual running costs of the vehicle.
The flat rates for 2025/26 are:
| Vehicle | Rate per business mile |
|---|---|
| Car or goods vehicle, first 10,000 business miles in the year | 45p |
| Car or goods vehicle, each business mile over 10,000 | 25p |
| Motorcycle | 24p |
There is no higher band above 45p for cars, and there is no separate "first year" uplift. After 10,000 business miles in the tax year the car rate drops to 25p.
Two rules matter. First, once you use the flat rate for a particular vehicle, you must keep using it for that vehicle for as long as you use it in the business. Second, you cannot use the flat mileage rate for a vehicle you have already claimed capital allowances on, or that you have already put through as an actual cost. So you pick one method per vehicle and stay with it.
The flat rate is meant to cover fuel, servicing, insurance, repairs and wear. You can still claim separately for things the rate does not cover, such as business parking and toll charges. You cannot add fuel on top of the 45p, that would be double counting.
The alternative is the actual-cost method: you total the real running costs of the vehicle for the year and claim the business-use proportion. That can be worth more if you run an expensive vehicle and clock heavy business mileage, but it needs proper records and a defensible business-use percentage. Our self-employed tax calculator can help you see how either method feeds into your overall profit and tax.
What counts as a temporary workplace for a dentist?
The temporary workplace idea matters most if you work through a limited company and pay yourself mileage, because the employee travel rules then apply. Under those rules, travel to a temporary workplace is allowable, while ordinary commuting to a permanent workplace is not.
A workplace is treated as temporary where you go there to perform a task of limited duration or for a temporary purpose. The key limit is the 24-month rule: once you expect to attend a particular workplace for more than 24 months, or it becomes clear you will, it is treated as a permanent workplace and the travel to it becomes ordinary commuting.
For a locum dentist moving between practices on short bookings, individual practices can be temporary workplaces. For an associate who settles into one practice for years, that practice is a permanent workplace and home-to-practice travel is a commute.
If you are self-employed rather than incorporated, you apply the base-of-operations test in the section above rather than the 24-month rule, but the practical outcome is similar: a settled practice is your base, and travel to it is not claimable.
If you cover shifts as a dental locum, the same temporary-workplace logic that applies to medical locums is relevant to how you structure travel claims. Our guidance for locum doctors walks through the same principles in a healthcare setting.
How do you claim use of home as a dentist?
If you do genuine business work at home, treatment planning, lab liaison, NHS paperwork, CPD, bookkeeping, you can claim a share of your home running costs. There are two routes.
The simplified flat rate
HMRC's flat rate for working from home depends only on the number of hours you work there each month. For 2025/26 the monthly amounts are:
| Hours worked from home per month | Flat rate per month |
|---|---|
| 25 to 50 hours | £10 |
| 51 to 100 hours | £18 |
| 101 hours or more | £26 |
It is simple and needs no apportionment maths. The catch is that the flat rate does not include telephone or internet, you work those out separately on a business-use basis. For most associates doing a few hours of admin a week, the flat rate is honest and low-effort.
The actual-cost apportionment
The alternative is to apportion your real household running costs on a fair and reasonable basis. HMRC's guidance accepts apportioning costs such as heating, lighting, council tax, insurance and similar by reference to the area used for business and the time it is used.
A common method is to take the number of rooms used for work and the proportion of time they are used for the business, then apply that fraction to the relevant household bills. The claim has to reflect the facts of how the home is actually used, not an arbitrary percentage. If you only write up records at home now and then, HMRC accepts a modest claim on any reasonable basis. If you genuinely run a meaningful part of your work from a dedicated study, a larger apportionment can be justified, as long as you can show it.
Whichever route you choose, keep it consistent and keep the workings. If a claim looks large relative to the work actually done at home, expect questions.
Worked example: a multi-site associate
Illustrative example. Aisha is a self-employed associate dentist in the 2025/26 tax year. She works Monday and Tuesday at the Oakfield practice and Wednesday to Friday at the Bridge Street practice. She does her CPD, treatment planning and bookkeeping from a study at home, around 60 hours a month.
Her driving in the year breaks down like this:
- Home to Oakfield and back, and home to Bridge Street and back: these are commutes to her two regular bases, so they are not claimable.
- A midday drive from Oakfield to Bridge Street on the weeks she covers an extra afternoon, and trips to an external lab and to training days: these are business travel.
Her allowable business mileage for the year comes to 4,000 miles, all by car and all within the first 10,000-mile band.
Mileage claim, using the flat rate:
- 4,000 business miles at 45p = £1,800.
Use of home, using the simplified flat rate. She works 60 hours a month from home, which falls in the 51 to 100 hours band at £18 a month:
- £18 x 12 months = £216.
Aisha's total deduction from these two areas is £1,800 + £216 = £2,016. That comes off her trading profit before tax and Class 4 National Insurance are worked out. She keeps a mileage log showing the date, route and purpose of each business journey, and a note of her monthly home-working hours, so the claim is supportable if HMRC asks.
Note what is missing: not a single home-to-practice mile is in the £1,800, because those are commutes to her regular bases.
A quick decision walkthrough
Use this to sort a journey or a home claim quickly.
For a journey, ask in order:
- Am I travelling from home to a practice I regularly work at? If yes, it is a commute, not claimable.
- Am I travelling between two work locations in the same day, or out to a temporary site or patient? If yes, it is business travel, claimable.
- Do I have no regular practice base, with home as my operational centre? If yes, home-to-site travel can be claimable, keep evidence.
For the mileage method, ask:
- Have I already claimed capital allowances or actual costs on this vehicle? If yes, you cannot use the flat rate for it.
- Otherwise, will the flat 45p and 25p rate be simpler and broadly fair? For most dentists, yes, and you must then stick with it for that vehicle.
For use of home, ask:
- Do I do only light admin at home? The flat rate by hours is usually the cleanest choice.
- Do I run a substantial part of my work from a dedicated space? An actual-cost apportionment may give a larger, still-defensible claim.
Does this work differently through a limited company?
Yes, in two ways. First, simplified expenses, both the flat mileage rate and the flat use-of-home rate, are only for the self-employed. Limited companies cannot use them. A company instead pays the director mileage under the Approved Mileage Allowance Payment rules, at the same 45p and 25p figures, and handles home working through a separate arrangement.
Second, the travel test for a company is the employee temporary-workplace rule, including the 24-month limit, rather than the self-employed base-of-operations test.
One more point that often surprises dentists who incorporate: associates and locums who work through a limited company are excluded from the NHS Pension Scheme, because scheme membership runs through the individual's self-employed or employed NHS status, not a company. That is a separate issue from travel, but it is worth weighing before you incorporate.
If you are weighing up self-employment versus a company, or just want your travel and home claims done properly, our associate dentists service is built around this, and we can take the whole return off your plate through our self-assessment service.
Want your dentist mileage and use-of-home claims done right, with nothing left on the table and nothing that won't stand up? Book a free 20-minute call with a Zmartly accountant and we'll review your travel pattern and home set-up.
Frequently asked questions
Can I claim the drive from home to my dental practice?
Usually no. If you regularly work at that practice it is treated as your base, and home-to-base travel is ordinary commuting, which is not an allowable business expense. The drive from that practice to a second practice or a temporary site later the same day is business travel and is claimable.
Is the dentist mileage rate 45p or 55p per mile?
It is 45p per business mile for the first 10,000 business miles in the tax year, then 25p for each mile after that, for cars and goods vehicles in 2025/26. There is no 55p rate. Motorcycles are 24p per mile.
Can I claim both mileage and actual car running costs?
No. For any given vehicle you choose one method. If you use the flat 45p and 25p rate you cannot also claim fuel, servicing or insurance for that vehicle, and once you start using the flat rate for a vehicle you must keep using it. You can still claim business parking and tolls on top, as the flat rate does not cover those.
How much use of home can a dentist claim?
Either HMRC's flat monthly rate based on hours worked at home, which is £10, £18 or £26 a month for 2025/26 depending on the hours band, or a fair apportionment of your actual household running costs based on the space used and time used for business. Pick whichever better reflects how much work you genuinely do at home, and keep the workings.
Does use of home count if I only do paperwork there?
Yes, light admin still counts. For occasional record-keeping HMRC accepts a modest claim on any reasonable basis, and the flat rate by hours is the simplest way to make it. A larger claim needs to reflect genuine, more substantial business use of the home.
Are the rules different if I work through a limited company?
Yes. Companies cannot use the simplified flat rates. The company pays mileage under the Approved Mileage Allowance Payment rules, at the same 45p and 25p figures, and travel is judged by the employee temporary-workplace rules, including the 24-month limit, rather than the self-employed base test.
