Sole Trader Allowable Expenses UK 2026
UK sole trader allowable expenses for 2025/26: the full HMRC list with worked examples covering home office, mileage, training, and capital purchases.
Every sole trader's tax bill comes down to two numbers. Income on one side. Allowable expenses on the other. Most self-employed people underclaim — not by exotic margins, but by a steady drip of small costs they never logged. Over a year that drip is often £1,500 to £3,000 of missed deductions, which is £300 to £900 of extra tax at the basic rate.
This guide covers sole trader allowable expenses UK 2026 — the categories HMRC recognises, the rules each one follows, the simplified flat rates, and the boundary cases that get pushed back in an enquiry.
The 'wholly and exclusively' test
The rule that decides every claim is in section 34 of the Income Tax (Trading and Other Income) Act 2005. A cost is deductible if it is incurred "wholly and exclusively for the purposes of the trade".
Three implications matter:
- A cost with a dual purpose is usually disallowed in full, not apportioned. The classic example is everyday clothing. Even if you wear a suit only when meeting clients, the suit is not deductible because it also keeps you warm and decent.
- The exceptions are costs where the business and private elements can be separately identified — mileage, use-of-home, business phone calls on a personal contract.
- Intention matters more than outcome. A failed marketing campaign is still wholly and exclusively for business. A business lunch with your spouse is not, even if you discussed clients.
The HMRC Business Income Manual sets out how each category is treated in practice. It is dense but searchable.
Allowable expense categories
The self-employment pages of the self assessment return ask you to split costs into broad categories. Map every receipt to one of these as you go. The bookkeeping line on the SA103 short form is collapsed to a single figure, but you still need the breakdown for an enquiry.
Cost of sales
Stock you bought to resell, materials used in jobs you delivered, and packaging that went out the door with the product. The full cost is deductible in the year you used or sold the item, not when you bought it. A plumber buying a van-load of copper pipe at the year end deducts only what they fitted, not the lot.
Premises
Rent, business rates, light and heat, insurance, security, cleaning. A separate business premises is straightforward. A home office uses the use-of-home rules below.
Motor and travel
Fuel, road tax, MOT, insurance, repairs, parking, congestion charges, train and bus fares for business journeys. You can either claim actual costs based on the business mileage percentage or use HMRC's simplified mileage rate. You cannot mix the two on the same vehicle in the same year.
Travel and subsistence
Hotels and meals while away from your normal place of work on business. The "normal place of work" test catches contractors who travel to the same client site every week — that site becomes a normal workplace after about two years.
Communications
Business landline, mobile contract, broadband, postage, courier costs. If a contract covers personal use as well, claim a business percentage. A second mobile contract used only for business gives a clean 100% claim.
Professional fees and insurance
Accountancy fees, legal fees on business matters (not personal disputes), professional indemnity insurance, public liability, employer's liability, subscriptions to relevant professional bodies. Subscriptions only qualify if the body is on the HMRC List 3.
Training
Training that maintains or updates skills you already have. A web developer's React conference is deductible. A web developer's training as a yoga instructor is not — it is acquiring a new trade, which sits outside the wholly-and-exclusively test. HMRC tightened the boundary in 2023; the relevant guidance is in BIM35660.
Marketing and advertising
Website hosting, domain renewals, social media ads, business cards, branded vehicle livery, search ads, sponsored posts, mailing lists. Entertaining clients is not deductible (it sits in a separate disallowed-entertainment category), but reasonable refreshments at a marketing event you host can usually be claimed under marketing.
Bank and finance charges
Business bank account fees, interest on business loans, hire purchase interest on business equipment, credit card fees on a card used exclusively for business. Mixed-use credit cards need apportionment, which usually means HMRC pushes back. A dedicated business card is much cleaner.
Use of home — simplified vs actual
The use-of-home claim is the most common area where sole traders leave money on the table.
HMRC's simplified flat rate scales with the hours worked from home each month:
| Hours per month | Flat rate (per month) |
|---|---|
| 25 – 50 | £10 |
| 51 – 100 | £18 |
| 101 or more | £26 |
A full-time sole trader claiming the highest band gets £312 a year. That is fine if your home costs are small and the business does not really use the space.
The actual method works out a fair share of household running costs:
- Add up annual electricity, gas, water, council tax, rent or mortgage interest (not capital repayment), home insurance, and broadband.
- Divide by the number of rooms in the house (excluding kitchens, bathrooms, and hallways — they are general use).
- Multiply by the number of rooms you use for business and the fraction of time those rooms are used for work.
A self-employed designer with annual running costs of £6,000 across six countable rooms, using one room 70% of the time for business, claims £6,000 ÷ 6 × 70% = £700. That is more than double the simplified band.
The actual method is also worth running for anyone in a rented flat where one room genuinely is dedicated office space.
Mileage allowance and motor costs
Most sole traders use the approved mileage allowance because the record-keeping is lighter.
| Vehicle | First 10,000 miles | Above 10,000 miles |
|---|---|---|
| Cars and vans | 45p | 25p |
| Motorcycles | 24p | 24p |
| Bicycles | 20p | 20p |
The 10,000-mile reset is per tax year. Mileage covers fuel, insurance, road tax, depreciation, repairs, MOT, breakdown cover. You cannot claim those costs separately on the same vehicle.
A logbook in the glovebox or a tracking app on your phone is non-negotiable. HMRC routinely asks for it in enquiries. "I drive about 8,000 business miles a year" without supporting records gets restated to zero.
If your business mileage is over 12,000 a year, run the actual cost method as well. A van used 90% for business often gives a higher deduction once depreciation and repairs are factored in.
Capital purchases and the Annual Investment Allowance
A laptop, a printer, tools, a van, office furniture — these are capital, not revenue. They give you a benefit lasting more than one year.
Most capital items qualify for the Annual Investment Allowance (AIA). AIA gives 100% relief in the year of purchase, up to £1m per business. For sole traders that cap is almost never reached.
A new £1,800 laptop bought in January 2026 for full business use is a £1,800 deduction in 2025/26, even if you have not finished paying for it on a finance deal. Mixed-use equipment is apportioned — a laptop used 60% for business is a £1,080 deduction.
Cars are different. They use the writing-down allowance (WDA) instead. A car with CO2 emissions of 50 g/km or less qualifies for 100% first-year relief, but only if the car is brand new and not previously registered. Higher-emission cars get 18% or 6% a year on a reducing-balance basis.
The trading allowance
The trading allowance gives you a £1,000 flat deduction against self-employment income, or full exemption if gross income is below £1,000.
It is most useful for hobby-level traders — a part-time seller on a marketplace, a freelance gig that brings in £400 a year, a small Etsy shop. Below £1,000, you do not have to register for self assessment at all. Above £1,000, you have to register, but you can elect to claim the £1,000 flat instead of itemising expenses.
You cannot use the trading allowance and claim expenses on the same income. Pick whichever gives the bigger deduction. A consultant turning over £3,000 with £200 of expenses is better off with the £1,000 flat allowance. The same consultant turning over £30,000 with £6,000 of expenses keeps the £6,000.
HMRC pushback points
Some categories get challenged more often than others. Tighten the records on these before they show up in an enquiry letter.
- Phone bills. A "50/50 business and personal" split on a single contract is the default position, but if the actual call log is 80% personal HMRC will adjust it. Keep a sample month's itemised bill once a year.
- Subsistence on day trips. A lunch on the way to a client site is only deductible if the trip is outside your normal area. Within your normal area, lunch is treated as personal.
- Training that smells like a new trade. Anything that broadens your skills into a new field is at risk. A short refresher in your existing field is safe.
- Round-sum allowances. HMRC dislikes flat "£100 a month" entries for things like fuel. They want vouchered amounts, not estimates.
- Sole trader expenses paid from a personal account. Allowable, but they have to be properly recorded and reimbursed via the business. Direct payment from the personal account with no business record is usually disallowed for lack of evidence.
Frequently asked questions
What is the 'wholly and exclusively' test?
HMRC only lets you deduct a cost from trading profit if it was incurred wholly and exclusively for the business. A cost with a dual purpose is usually disallowed in full unless you can identify a specific business portion (mileage and use-of-home are the main exceptions, because the rules allow a fair apportionment).
Can I claim use of home as a sole trader?
Yes. You can either use HMRC's simplified flat rate (£10 to £26 a month depending on hours worked from home) or claim an actual share of household running costs based on rooms used and time spent on business work. The actual method usually gives a higher claim if you work from home full-time.
What mileage rate can I claim?
The HMRC approved mileage rate for cars and vans is 45p per mile for the first 10,000 business miles in the tax year and 25p per mile after that. Motorcycles are 24p flat, bicycles 20p. The rate covers fuel, insurance, depreciation, and repairs — you cannot claim them separately on the same vehicle.
What is the trading allowance?
The trading allowance is a £1,000 flat deduction available to anyone with self-employment or miscellaneous income. If your gross trading income is £1,000 or less, you do not have to declare it. Above £1,000, you can choose to claim the £1,000 instead of actual expenses — useful for low-cost businesses where receipts add up to less than the flat allowance.
Do I need receipts for small expenses?
Yes. HMRC can ask for evidence of any expense at any point in the six years after the tax year ends. Small cash purchases are still expected to have a till receipt or photo. The £10 coffee that 'seemed obvious' is the one HMRC will spot in an enquiry. Keep a photo on your phone if the paper fades.
This article is general guidance, not personal tax advice. Speak to a qualified accountant before acting on it.