Sole Trader Tax Return Guide for UK Tradespeople 2026: Self-Assessment, Expenses and Deadlines
Written by Tom Ellis · Senior Trades Editor
Last updated: July 2026
Quick Answer
UK sole trader tradespeople must complete a self-assessment tax return by 31 January each year (online) covering the previous tax year (6 April to 5 April). Your taxable profit is your total income minus allowable expenses — van costs, tools, insurance, PPE, and professional subscriptions all count. CIS deductions already paid reduce what you owe. Missing the January deadline triggers an automatic £100 fine.
For most tradespeople, the tax return is the most stressful admin task of the year. Done properly with accurate records, it can also produce a significant refund — particularly for CIS subcontractors. Done badly or late, it creates penalties, interest charges, and HMRC enquiries.
This guide explains everything a sole trader tradesperson needs to know about the self-assessment process in 2026 — including the deadlines, what expenses to claim, how CIS interacts with your return, and what Making Tax Digital means for you from April 2026.
Key Self-Assessment Dates for 2026
| Date | What Happens |
|---|---|
| 6 April 2025 | Tax year 2025/26 begins |
| 5 October 2026 | Deadline to register for self-assessment if new to it |
| 31 October 2026 | Paper return deadline for 2025/26 |
| 31 January 2027 | Online return deadline + pay tax owed for 2025/26 + first 2026/27 payment on account |
| 31 July 2027 | Second 2026/27 payment on account due |
Allowable Expenses: What Tradespeople Can Claim
HMRC allows you to deduct business expenses from your income before calculating the tax you owe. Only "wholly and exclusively" business expenses qualify. For tradespeople, the most common allowable expenses are:
Tools and Equipment
Tools purchased for work are allowable. Small tools (under ~£300) can usually be claimed as a trading expense in full the year you buy them. Larger items of plant and equipment are claimed through Capital Allowances — typically the Annual Investment Allowance (AIA) which currently allows 100% deduction in year of purchase up to £1 million per year. Keep all receipts.
Van and Vehicle Costs
If the van is used exclusively for work, you can claim 100% of: fuel, road tax, insurance, MOT, servicing, tyres, and repairs. If you use it for private journeys too, you must apportion costs. Many sole traders use the simplified mileage rate instead: 45p per mile for the first 10,000 miles, 25p per mile after that — no need to keep receipts for every expense, just a mileage log.
Protective Clothing and Workwear
Hi-vis jackets, steel-toe boots, gloves, and safety helmets used for work are allowable. Clothing you could wear outside work (branded polo shirts, normal trainers) is generally not allowable even if you only wear them for work.
Insurance Premiums
Public liability insurance, employers' liability, professional indemnity, tools cover, and van insurance (business use portion) are all allowable expenses.
Professional Subscriptions and Qualifications
NICEIC, Gas Safe, NAPIT, CHAS, Construct Industry Training Board (CITB) levies, CSCS card fees, and trade body memberships are allowable. Training costs are allowable if they update existing skills — not if they are learning a completely new trade.
Other Common Allowable Expenses
- Business mobile phone and calls (business use portion)
- Accountancy and bookkeeping fees
- Advertising (website, Checkatrade, Sleepless Tradesman subscription)
- Stationery and office supplies
- Bank charges on a business account
- Pension contributions (via a registered pension scheme)
How CIS Deductions Work on Your Tax Return
If you work as a CIS subcontractor, contractors deduct 20% (or 30% if you are unverified) from the labour element of your payments. These deductions are advance payments of your Income Tax and National Insurance. Here is how they flow through your return:
- Your total gross income appears as self-employment income on your return
- You deduct allowable expenses to calculate net profit
- Tax and NI are calculated on net profit
- CIS deductions already paid by contractors are offset against this bill
- If CIS deductions exceed your tax bill, HMRC refunds the difference
Many subcontractors receive a significant refund each year because the flat 20% CIS rate often overstates their actual tax liability once expenses are deducted. Keeping good records and filing promptly is the fastest route to receiving that refund. See our CIS tax guide for a full breakdown.
Payment on Account: The Second-Year Shock
When your self-assessment bill exceeds £1,000, HMRC collects advance payments toward next year's bill. This catches many tradespeople off guard in their second year of trading. If your 2024/25 tax bill was £3,000:
- 31 January 2026: pay £3,000 (2024/25 bill) + £1,500 (50% advance for 2025/26)
- 31 July 2026: pay £1,500 (remaining 50% advance for 2025/26)
- 31 January 2027: pay the balancing payment for 2025/26 (after deducting the £3,000 already paid on account)
The practical advice: set aside 25–30% of every invoice payment into a separate account throughout the year. This covers both the balancing payment and payments on account without any panic at the January deadline.
Making Tax Digital for Sole Traders
Making Tax Digital (MTD) for Income Tax Self-Assessment (ITSA) is being rolled out in phases:
- April 2026: Sole traders earning over £50,000 per year must keep digital records and submit quarterly updates to HMRC using MTD-compatible software
- April 2027: Extended to sole traders earning over £30,000 per year
- Later phases: Lower income thresholds TBC
If you are already using accounting software or a bookkeeping app that integrates with HMRC (QuickBooks, FreeAgent, Xero), you may already be MTD-ready. If you keep records on spreadsheets or paper, you will need to switch to compatible software before your threshold applies.
Penalties for Late Filing and Late Payment
| Delay | Penalty |
|---|---|
| 1 day late (filing) | £100 automatic fine |
| 3 months late | £10/day for up to 90 days (max £900 additional) |
| 6 months late | 5% of tax due or £300, whichever is higher |
| 12 months late | A further 5% or £300 |
| Late payment | Interest at Bank of England base rate + 2.5% from due date |
Frequently Asked Questions
How much tax does a sole trader tradesperson pay in the UK?
You pay Income Tax on your profit (income minus allowable expenses) above the Personal Allowance (£12,570 in 2026–27). Profit from £12,571 to £50,270 is taxed at 20% (Basic Rate); £50,271 to £125,140 at 40% (Higher Rate). On top of Income Tax, you pay Class 4 National Insurance — 9% on profit between £12,570 and £50,270, then 2% above. Class 2 NI was abolished from April 2024.
What is the 31 January deadline for?
Three things fall on 31 January each year: the online Self Assessment return must be filed, any remaining tax from the previous tax year must be paid, and the first payment on account toward the next year's bill is due. Missing this deadline triggers an immediate £100 fine regardless of whether you owe any tax.
Do I need to register for Self Assessment if I'm CIS-registered?
Yes. CIS registration is separate from Self Assessment. If you are self-employed and earn above the personal allowance, you must file a Self Assessment return each year. CIS deductions made by contractors during the year appear on your return as tax already paid — they reduce your final bill (or generate a refund if they exceed what you owe).
What if I can't pay my tax bill?
Contact HMRC before the deadline. HMRC offers a Time to Pay arrangement for tradespeople who cannot pay in full, allowing you to spread payments over up to 12 months (sometimes longer). Interest still accrues, but it avoids the escalating penalty regime. Ignoring the bill is always worse — HMRC charges both penalties and interest, and can ultimately pursue the debt through the courts.
Can I claim tools on my tax return?
Yes. Tools used for work are an allowable expense. Small tools (under around £300–500) are typically claimed as revenue expenses in the year of purchase. Larger equipment may need to go through capital allowances — including the Annual Investment Allowance (AIA), which allows 100% of qualifying spend up to £1 million to be deducted in the year of purchase.
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