How much CIS refund can electricians expect?

HMRC publishes no typical figure for a CIS refund. Your refund is what contractors deducted minus the Income Tax and Class 4 NI owed on your profit. The worked examples below show how it works for electricians in 2026-27.

Under the Construction Industry Scheme (CIS), the 20% a contractor takes from the labour part of your invoice is an advance payment towards your Income Tax and National Insurance. It is 30% if the contractor cannot verify you. Cable, fittings and other materials you bought are not deducted from. Many electricians mix site work for contractors with jobs paid by homeowners, and those domestic jobs have no deduction. The table works out four electricians' years using 2026-27 rates, as published on GOV.UK.

Estimated refunds for electricians in 2026-27

All examples assume a sole trader outside Scotland, with no other income and the full personal allowance. Costs include any materials the electrician bought. Materials figures are what the materials cost: CIS 340 says only that direct cost comes off before the deduction, so any markup you add is deducted from like labour.

The rates used: Income Tax at 20% on profit between £12,571 and £50,270, and Class 4 National Insurance at 6% between £12,570 and £50,270. GOV.UK says that if your profits are £7,105 or more a year, Class 2 contributions are treated as having been paid, so Class 2 adds nothing here. This is an estimate based on the figures shown and the rules for 2026-27. Your actual figure may differ.

What pushes an electrician's refund up or down

The per-£100 figures below apply while profit is between £12,570 and £50,270. Below £12,570 there is no Income Tax or Class 4 NI to save. Between £50,270 and £100,000 the combined rate is 42%, so each £100 of profit adds £42. Once your income passes £100,000, the personal allowance shrinks by £1 for every £2 over, so the rate is higher again; work those years out in full.

• Domestic work. Each £100 of profit from homeowner jobs adds £26 to the bill, £20 Income Tax and £6 Class 4 NI, with nothing deducted towards it. Rows three and four show how quickly the refund disappears.
• Costs. Each £100 of allowable costs, such as your van, tools, test equipment, scheme fees and phone, cuts the bill by £26.
• Materials. On site jobs where you supply cable and fittings, the deduction is taken only from the labour. That lowers what is deducted, so less waits with HMRC, but it is not money lost.
• Jobs outside CIS for contractors. HMRC's manual treats repairs and extra sockets on their own as outside CIS, so a contractor paying you for them may not deduct, unless they are part of a wider contract that is in CIS. A complete rewire counts as an installation, so a rewire for a contractor is inside CIS. Income from jobs outside CIS still goes on your return.
• The 30% rate. Your bill does not change, so the extra comes back. On the new-build row, 30% would mean £11,400.00 deducted and an estimated refund of £6,478.20.

If you are VAT registered, CIS 340 says the deduction is worked out on the amount before VAT, so VAT does not change the refund.

What this means for you

An electrician doing mostly site work at 20% will usually see a refund, because the personal allowance means the true bill is less than the deductions. If your domestic work is growing, expect a smaller refund, and set money aside from each homeowner job, because CIS will not cover that tax for you.

Your 2026-27 refund is claimed on your tax return after 5 April 2027. Once you are in Making Tax Digital, HMRC adds your deductions to your MTD tax return and you request the refund separately through your HMRC online services account. Our guide on how to claim a CIS refund as an electrician sets out each route.

Steps to estimate your own refund

1. Add up the gross pay and the deductions on every payment and deduction statement for the tax year.
2. Add your domestic income from homeowners, including cash jobs, and any other work paid in full.
3. Total your allowable costs, including materials you bought, and take them off your total turnover to get your profit.
4. Take off the £12,570 personal allowance, then work out 20% Income Tax and 6% Class 4 NI on the rest. This only works while profit stays at or below £50,270; above that, Income Tax rises to 40% and Class 4 NI falls to 2%, so the shortcut overstates the refund.
5. Take that tax and NI away from your total deductions. A positive figure is your estimated refund; a negative one is tax to pay. If you repay a student or postgraduate loan through Self Assessment, that repayment is added to the bill too, so the refund is smaller.

When you might owe instead

Once a good share of your work is domestic, the deductions may not cover your bill, as row four shows. You pay any balance by 31 January after the tax year. GOV.UK says you must also make payments on account towards the next year unless that bill was less than £1,000, or you paid more than 80% of the tax you owed outside Self Assessment. Other things can also cut what reaches your bank:

• Other income. Wages or rent use up your personal allowance first.
• Scottish taxpayers. Scotland has its own Income Tax bands, so these figures do not apply.
• Older tax debts. HMRC's manual says repayment is possible only where deductions exceed the Income Tax and Class 4 NI on the year's profits plus any still unpaid on profits for other years, usually earlier ones.
• Payments due soon. GOV.UK says you may not get a refund if you have tax due in the next 45 days.

Use the free MTD check to see whether Making Tax Digital applies to you from April 2027, and visit the trades section for more guides for electricians.