1. Home-office costs (the simplified flat rate)
If you work from home regularly, HMRC lets you claim a simplified flat-rate deduction per month based on hours worked. For higher claims you can apportion actual costs (light, heat, rates, broadband) by the floor area and time spent — but most sole traders find the flat rate easier and HMRC-safe.
2. Mileage in your own vehicle
Using your own car for work? Claim the Approved Mileage Allowance at the published per-mile rates (the rate drops after a certain annual mileage). Keep a simple log of date, journey, business purpose and miles. This is one of the most commonly missed claims for tradespeople and consultants.
3. Professional subscriptions & memberships
Subscriptions to professional bodies on HMRC's approved list are deductible — for example chartered institutes, trade associations and professional regulatory bodies. Check the list before you assume.
4. Training that maintains existing skills
Training that keeps your existing skills up to date is normally deductible. Training that adds an entirely new skill set may not be. The line can be subtle — a continuing professional development course is usually fine; an MBA may not be.
5. Software, cloud tools and subscriptions
Bookkeeping, design, productivity and communication apps used for the business are deductible. Don't lump them in with personal subscriptions — charge them to a business card or note them in your bookkeeping monthly.
6. Pre-trading expenditure
Expenses incurred in the period before you started trading can usually be claimed, as long as they were for the business. Domain names, market research, initial software subscriptions, training to get started — all common candidates.
7. Bad debts you've written off
A specific debt you've genuinely given up on can be written off as a deductible expense. General "provisions" for possible bad debts are not deductible — you need to identify the specific customer and reason.
8. Bank charges, interest & financial costs
Business bank charges, business credit card interest, loan interest, factoring fees and merchant-processor fees are all deductible. The trick is having a separate business account — mixing them with personal banking makes the claim much messier.
9. Work clothing — but only certain types
Protective clothing (PPE), uniforms with a company logo and costumes for entertainers are deductible. An ordinary suit that you could wear elsewhere is not, no matter how much you only wear it for work. This catches a lot of people out.
The general rule is that expenses must be incurred wholly and exclusively for the business. Mixed-use expenses (phone, broadband, vehicles) can usually be apportioned. Personal expenses dressed up as business cannot.
Don't forget: every expense reduces tax
For a sole trader, every £100 of legitimate expense saves you up to 47% in income tax and NI at higher rates. For a limited company, every £100 of expense saves you corporation tax at 19–25%. Across a year, the forgotten claims add up to thousands.
The fix isn't to claim more aggressively — it's to keep tidy bookkeeping all year, snap every receipt, and have a real accountant review the picture each year-end.
Frequently asked questions
Generally no — personal subsistence isn't deductible. Subsistence on a genuine business trip away from your normal place of work can be claimed; routine lunches at your desk cannot.
Limited rules apply. Small promotional gifts up to a modest value that carry your business branding and aren't food/drink/tobacco can usually be claimed. Beyond that, restrictions apply.
HMRC expects records to be kept for at least 5 years after the 31 January submission deadline of the tax year they relate to (longer for companies). Digital storage is fine.