How much tax should a electrician set aside? Tax and allowable expenses for 2025/26
Self-employed electricians often split their year between domestic jobs, where customers pay you, and site work, where a contractor does. Each has its own paperwork, but the profit is added together and taxed once.
What the tax looks like
Using the 2025/26 rates (England, Wales or Northern Ireland, no other income), a electrician with £55,000 of takings and £10,000 of allowable costs has £45,000 of profit and about £8,432 of income tax and Class 4 National Insurance for the year, roughly £703 a month. The figures are an illustration, not an average for the trade. Tax is on profit, not takings.
| Profit for the year | Income tax + Class 4 NI | Per month | Per £1 of profit |
|---|---|---|---|
| £27,000 | £3,751.80 | £313 | 14p |
| £45,000 | £8,431.80 | £703 | 19p |
| £68,000 | £17,248.60 | £1,437 | 25p |
Open the calculator already filled in with this example and change the two numbers to yours. It also shows the January and July payment dates.
Costs a electrician usually claims
Claim only what you actually spent on the business, and only the business share of anything you also use personally.
- Test equipment: multifunction testers, voltage indicators, calibration. Calibration is a running cost; the tester itself may be a capital allowance item.
- Cable, accessories and consumer units bought for jobs, kept against the job.
- Scheme and competence fees: registration with a competent person scheme, plus annual assessment fees, where you need them to do the work.
- Insurance: public liability and tools cover.
- Van costs: fuel, insurance, servicing, or the flat mileage rate for the year.
- Training that keeps up your existing skills, such as wiring regulations updates. Training for a brand-new line of work is treated differently, so check the GOV.UK guidance.
The general list is on GOV.UK: self-employed expenses you can claim, and what you can't. If your costs for the year are under £1,000, the trading allowance may leave you less tax.
Site work and the Construction Industry Scheme
On site work for a contractor, CIS deductions are taken from your payments before you receive them. GOV.UK sets out the base the percentage applies to: the invoice total, less VAT, materials you paid for yourself, fuel (except for travelling), plant hire and a few other items. That is why a clear materials line on your invoice means a smaller deduction. The deductions are advance payments towards your bill, not an extra tax. On a domestic job paid by the householder there's nothing to deduct; the whole payment is yours and so is the set-aside.
VAT
Over £90,000 of taxable turnover in 12 months means you must register for VAT. Check the total each month, not at the end of the tax year.
Records worth keeping
- Match each job to its materials receipts. Customers dispute invoices; HMRC can ask for the receipts behind your costs.
- Keep certificates, scheme fee receipts and calibration invoices in one folder for the year.
- Keep CIS payment and deduction statements. They are what you'll enter on the return.
- Record the date, customer and miles for van journeys if you use the flat rate.
Fits electricians who want income, materials and van costs in the boxes the return uses: the SortedDesk Self Assessment Spreadsheet is a one-off £4.99 download for Excel and Google Sheets. It is a spreadsheet only: nothing here files anything with HMRC, and the sheet doesn't replace an accountant if your case is complicated.
Dates matter too: the 2025/26 return and tax are due on 31 January 2027, and payments on account can make that January bigger than the year's bill.
This is a planning guide, not tax advice. Figures worked with the calculator's 2025/26 rules, and GOV.UK sources read on 21 October 2026: Expenses if you're self-employed, CIS: make deductions and pay subcontractors, Simplified expenses: vehicles, When to register for VAT.
Try the calculator with this example