CIS Rebate FAQ

A CIS rebate (also called a CIS tax refund) is money HMRC owes you because your contractor deducted too much tax under the Construction Industry Scheme. The standard CIS deduction is 20% of your gross income — but this does not account for your personal allowance (£12,570 in 2025/26) or your business expenses, so almost every subcontractor overpays and is owed a refund.

The average CIS rebate is between £1,000 and £3,000 per year, but the amount varies depending on your gross income, how much was deducted, and what expenses you can claim. Use our free CIS Rebate Calculator to get your personalised estimate in under 2 minutes.

Any self-employed subcontractor working in the UK construction industry who has had CIS deductions taken by a contractor can claim a rebate. This includes plumbers, electricians, plasterers, roofers, bricklayers, carpenters, labourers, painters, decorators and all other construction trades.

You claim your CIS rebate by filing a Self Assessment tax return with HMRC. If you have not registered for Self Assessment, you need to do this at gov.uk — the registration deadline is 5 October after the end of the tax year. Once registered, file your return online by 31 January each year. HMRC will calculate your rebate and pay it directly to your bank account, usually within a few weeks.

You can claim tools and equipment, PPE and workwear (hi-vis vests, hard hats, steel-toe boots, branded work clothing), travel between job sites at 45p per mile for the first 10,000 miles, business phone costs, public liability insurance, trade insurance premiums, accountancy fees, training courses, and equipment hire costs. Every pound of expenses reduces your taxable profit and increases your rebate.

Yes — you can claim CIS tax rebates going back 4 tax years. So if you have not yet filed Self Assessment returns, you could be owed a significant amount from 2021/22, 2022/23, 2023/24 and 2024/25 as well as the current 2025/26 year. You will need to file a separate Self Assessment return for each year you want to claim.

The personal allowance for the 2025/26 tax year (6 April 2025 to 5 April 2026) remains at £12,570. This means the first £12,570 of your profit is completely tax-free. The basic rate of 20% applies to income between £12,571 and £50,270. The higher rate of 40% applies to income above £50,270.

Our calculator gives a reliable estimate based on your figures using the 2025/26 personal allowance (£12,570), basic rate (20%) and higher rate (40%) tax bands. However, it is an estimate only — your actual rebate depends on your full tax position including National Insurance contributions, any other income sources, and student loan repayments. Always consult a qualified accountant or HMRC for your exact liability.

Yes, completely free. There are no fees, no subscriptions and no paywall. CISRebateCalculator.co.uk is funded by advertising only and will always be free to use.

No — our calculator requires no registration, login or personal details. Simply enter your figures and get your estimate immediately. We do not store any of the financial information you enter.