Here's something most sole traders don't realise until it's too late — the difference between a manageable tax bill and an eye-watering one often comes down to expenses. Not how much you earn, but how much you correctly claim. Get your sole trader allowable expenses right, and you keep significantly more of what you've worked for. Get them wrong — or miss them entirely — and you hand money to HMRC that you were never legally required to pay.
This guide covers everything: what you can claim, what you can't, how the rules actually work, and the mistakes that bring HMRC knocking.
Why Claiming the Right Expenses Changes Everything
Before diving into categories, here's a number worth sitting with. If you earn £45,000 as a sole trader and claim £9,000 in allowable expenses, you pay tax on £36,000 — not £45,000. At the basic 20% rate, that's £1,800 back in your pocket. If you're a higher-rate taxpayer, that saving doubles to £3,600.
Most sole traders without professional support miss somewhere between 15 and 30 percent of the expenses they're entitled to claim. That's not a small oversight — it's a significant and entirely avoidable cost, year after year.
The Golden Rule: "Wholly and Exclusively" for Business
Every expense you claim must pass one test set by HMRC: it must be incurred wholly and exclusively for the purposes of your business.
That means:
The cost was for business, not personal use.
The primary purpose was business — not partly personal.
Where an expense has both a personal and business element, you can sometimes split it. A mobile phone is used for business 60% of the time. Claim 60% of the bill. A laptop used only for work? Claim the full cost. A suit you wear to client meetings but also to weddings? HMRC says no — because it also serves a personal purpose.
It sounds straightforward. In practice, the grey areas catch a lot of people out — and that's usually where an HMRC enquiry starts. If you're unsure whether something qualifies, our taxation services team can advise you before you file.
What Expenses Can a Sole Trader Claim?
Here's a breakdown of the main categories you can claim:
Office and Admin Costs: Stationery, printer ink, postage, computer software, and small office equipment. If you rent a dedicated workspace, that's claimable too.
Phone and Internet: The business proportion of your phone bill and broadband. If your mobile is 70% business use, claim 70%.
Professional Fees: Your accountant's fees are fully claimable — so are legal fees related to your business, trade body memberships, and professional subscriptions directly relevant to your work.
Marketing and Advertising: Website costs, domain renewals, paid advertising, business cards, and printed materials all qualify.
Training and Development: Courses, workshops, and professional development — as long as they relate to your existing trade. Training to enter an entirely new profession doesn't qualify.
Staff Costs: Wages, employer National Insurance contributions, and pension contributions are all claimable. Keeping these figures accurate and properly documented matters — especially when your self-assessment tax return is being prepared.
Equipment and Tools: Tools and equipment used purely for your business. Under cash basis accounting, these can be claimed in full in the year you buy them.
Insurance: Business insurance, professional indemnity, and public liability premiums are all allowable.
Working From Home — Flat Rate vs Actual Costs
Flat Rate (Simplified Expenses): HMRC gives you a fixed monthly amount based on how many hours you work from home. If you put in 25-50 hours a month, you can claim £10. That rises to £18 for 51 to 100 hours, and £26 for anything over 100 hours. It's the easier option — no calculations needed — but honestly, for most people, it comes out lower than what they'd get if they added up their actual bills.
Actual Cost Method: Work out the proportion of your home used for business — based on rooms or square footage — and claim that percentage of your rent or mortgage interest, heating, electricity, and broadband. More admin, but typically a larger deduction.
Which method works better depends on your situation. Either way, having clean and organised records throughout the year is what makes this straightforward — and that's exactly what proper bookkeeping services for small businesses are built around.
Travel and Vehicle Costs — Mileage Rate 2026
For business travel, HMRC's approved mileage rates for 2026 are:
First 10,000 business miles: 55p per mile
Beyond 10,000 miles: 25p per mile
Keep a mileage log — date, start and end point, purpose, and miles covered. HMRC expects this level of detail. Without it, the claim won't hold up.
If you use your vehicle for both business and personal journeys, you can claim only the business portion. Commuting from home to a regular place of work does not count as a business journey.
What You Cannot Claim — Mistakes That Trigger HMRC
This is the section most guides bury at the bottom. We're putting it here because these are the errors that lead to investigations:
Daily food and coffee — personal subsistence is not allowable, even if you're working that day. HMRC flags this consistently.
Client entertaining — taking a client to lunch or a sporting event is specifically disallowed. Staff entertaining (like a Christmas party, within limits) is different.
Clothing — unless it's a uniform, protective gear, or branded workwear- isn't claimable. A smart suit for client meetings doesn't qualify.
Fines and penalties — HMRC penalties, parking fines, and legal fines cannot be claimed.
Personal expenses — anything that isn't wholly for business doesn't belong on your return.
Getting any of these wrong doesn't just cost you the disallowed expense — it can open the door to a full HMRC enquiry into your records.
FAQs
Q: Can I claim my accountant's fees as a sole trader expense?
Yes — accountant fees are fully allowable as a business expense for sole traders. This includes fees for preparing your tax return, bookkeeping support, and tax advice related to your business. In other words, getting professional help with your taxes is itself tax-deductible.
Q: What expenses can I NOT claim as a sole trader?
The main disallowable expenses are: daily food and drink, client entertaining, personal clothing, commuting costs, fines and penalties, and anything with a personal element that can't be separated from business use. These are the categories HMRC scrutinises most closely, and incorrect claims are one of the most common triggers for an enquiry.
Q: How much can I claim for working from home?
You can use HMRC's flat rate — between £10 and £26 per month depending on hours worked — or calculate your actual home costs and claim the business proportion. The flat rate is simpler; the actual cost method usually produces a higher deduction. Which works better depends on your specific circumstances.
Conclusion: Stop Leaving Money on the Table
Sole trader allowable expenses are one of the most effective tools you have for reducing your tax bill — and they're entirely legal. The problem isn't the rules; it's knowing them well enough to apply them correctly, document everything properly, and avoid the mistakes that attract HMRC attention.
That's exactly where Malik AccounTax comes in.
We work with sole traders across the UK from our base in Edinburgh, ensuring every legitimate expense is claimed, every record is in order, and your return is submitted accurately and on time. Most of our clients are surprised by how much they'd been leaving unclaimed — and how straightforward it becomes when someone who knows the rules is handling it.
Email: info@malikaccountax.com
Call / WhatsApp: +44 7879 720675
Book your free consultation today — and let Malik AccounTax make sure you're not paying a penny more in tax than you need to.