HMRC Self Assessment for Tradespeople UK 2026: Expenses, Deadlines and Payments on Account

Self Assessment Deadlines — The Dates That Matter

Every UK sole trader tradesperson needs to know these dates. Missing any of them costs money.

Late filing penalties: £100 for a single day late. £10 per day after 3 months (up to £900 additional). 5% of tax owed if the return is more than 6 months late, plus a further 5% at 12 months. Always file on time even if you cannot pay — the late filing penalty is entirely separate from late payment interest (currently 7.25% per annum on unpaid tax).

Allowable Expenses for UK Tradespeople

Allowable expenses reduce your taxable profit, which directly reduces your income tax and National Insurance bill. A tradesperson on a £40,000 profit who misses £5,000 in allowable expenses pays roughly £1,500-£2,000 more tax than necessary. Claim everything you are legitimately entitled to.

• Tools and equipment — hand tools, power tools, specialist equipment. Items under the annual investment allowance (currently £1,000,000) can be deducted in full in the year of purchase. Larger items are depreciated via writing-down allowances. Tools bought solely for work are 100% deductible.
• Van costs — you can claim capital allowances on the van purchase price (or use HMRC simplified flat rate of 45p per mile for the first 10,000 miles, 25p after). Running costs including fuel, insurance, MOT, servicing, tyres, and parking on site are all allowable. If the van is used for any personal travel you must apportion costs accordingly.
• Trade clothing and PPE — hi-vis vests, steel-cap boots, overalls, hard hats, gloves, and any protective workwear. Branded clothing bearing your company name or logo also qualifies. Everyday clothing worn to jobs does not qualify even if you only wear it for work.
• Professional memberships and registrations — Gas Safe registration (currently around £228/year for a sole trader), NICEIC or NAPIT annual registration fees, FMB membership, CSCS card renewal, and other trade body memberships are all allowable.
• Trade insurance — public liability insurance, employers liability (if you take on any labour), tool cover, and commercial van insurance are all fully allowable business expenses.
• Phone and broadband — the business-use proportion of your mobile phone bill, and broadband if used for work. If your phone is used 70% for work, claim 70% of the cost. If you have a separate business phone, 100% is allowable.
• Accountancy and software costs — accountant fees, bookkeeping software, invoicing apps, and any digital record-keeping costs used for the business are allowable in full.
• Training and certification costs — courses, exams, and certifications that maintain or update existing skills in your trade are allowable. Note: training for a new trade or skill you do not already have does not qualify.
• Marketing costs — subscriptions to lead generation platforms (Checkatrade, MyBuilder, Rated People), website costs, Google Ads, business cards, and any advertising expenditure are all allowable.
• Materials used in your own business — materials used to run your business (not resold to customers) are allowable. Materials bought and charged to customers are cost of sales — deducted from turnover before calculating gross profit, not as a separate expense category.

What You CANNOT Claim

HMRC disallows certain costs even when they relate to your business. Claiming these will cause problems at enquiry.

• Client entertaining or hospitality — taking a customer for a meal, drinks, or any form of entertainment is not allowable, regardless of how much business is discussed.
• Fines — speeding fines, parking fines on personal vehicles, and any other penalties are not allowable expenses, even if they occurred during a work journey.
• Personal clothing — clothing worn to jobs does not qualify unless it is genuinely protective (PPE) or branded with your business name. A tradesperson who buys jeans and boots they only wear to work cannot claim them.
• Home-to-work travel — travelling from your home to a regular fixed place of work is not allowable. However, travel between different job sites during the working day is allowable, and travel to a temporary workplace (a job that will last less than 24 months) is also allowable.

Payments on Account — The January Shock

Payments on account are advance payments toward your next year's tax bill. HMRC requires them when your self assessment tax bill (income tax plus Class 4 National Insurance) exceeds £1,000. The rule is straightforward but the cash flow impact blindsides many new tradespeople.

HMRC assumes your next year's tax bill will be broadly similar to this year's. They split the estimated bill into two equal instalments: 50% due 31 January alongside your current return, and 50% due 31 July.

The only reliable way to avoid this shock is to save consistently throughout the year. Set aside 28–30% of all income every month into a separate account designated for tax. Do not touch it for any other purpose. When January arrives, you will have more than enough to cover both the previous year's tax and the first payment on account.

If your income has dropped significantly compared to the previous year, you can apply to HMRC to reduce your payments on account. Do this through your online HMRC account. If you reduce them by too much, interest will be charged on the shortfall, so be conservative.

The Best Record-Keeping Apps for Tradespeople

Making Tax Digital (MTD) is being phased in for sole traders, with mandatory digital record-keeping requirements expanding in the coming years. Getting into good habits now avoids a scramble later.

Sleepless Tradesman handles the invoicing and income side — sending professional invoices to customers, tracking what has been paid and what is outstanding, and keeping a clean record of all money coming into the business. For a sole trader tradesperson, organised income records are half the job.

For expense tracking, tax calculation, and filing the return itself, pair Sleepless Tradesman with dedicated accountancy software such as FreeAgent (recommended for sole traders and small trades businesses — simple interface, HMRC-recognised) or QuickBooks Self-Employed. Both integrate bank feeds so expenses are captured automatically rather than manually entered. The combination of Sleepless Tradesman for income records and one of these platforms for expenses and tax gives a complete picture without needing a bookkeeper for day-to-day tasks.

Common Self Assessment Mistakes Tradespeople Make

• Filing late — the most expensive and entirely avoidable mistake. The £100 penalty is automatic, regardless of whether you owe any tax. Many tradespeople wait until they have all records organised, then run out of time. Start the process in November for a January deadline.
• Missing allowable expenses — particularly professional memberships (Gas Safe, NICEIC), mileage for business travel, and home office costs if any admin work is done at home. Keep receipts for everything throughout the year — trying to reconstruct expenses in January is stressful and incomplete.
• Forgetting CIS deductions already paid — tradespeople working as CIS subcontractors have 20% (or 30% if unverified) deducted at source by the contractor. These deductions are tax already paid on your behalf. They must be declared on your self assessment return as a tax credit, reducing your final bill. Failing to claim these means paying tax twice on the same income.
• Not claiming mileage for business travel — every trip between job sites, to suppliers, to training, and to business meetings is allowable at 45p per mile (first 10,000 miles) and 25p per mile thereafter. Keep a mileage log — a simple spreadsheet or app entry after each job adds up significantly over a year.
• Not accounting for payments on account — as explained above. The January bill is almost always larger than expected for tradespeople in their first year of filing. Save consistently to avoid this.

Summary

Self assessment does not need to be a source of stress for tradespeople. The rules are consistent: file by 31 January, claim every legitimate allowable expense, save 28-30% of income monthly for tax, and understand that your first January payment will likely be 150% of your tax bill due to payments on account. Get into good record-keeping habits from day one using Sleepless Tradesman for invoicing and a dedicated platform like FreeAgent for expenses, and the annual return becomes a straightforward process rather than a crisis.

Frequently Asked Questions