Written by Hammad Rasool MAAT·AAT licensed accountant·Updated November 2026

Enter your figures above and the result appears here.

Budget 2026 update: The 55p rate for the first 10,000 business miles is now permanent, and from 6 April 2027 the rate above 10,000 miles rises from 25p to 35p. See everything that changed.

Why CIS subcontractors usually get a refund

Under the Construction Industry Scheme a contractor deducts 20% from the labour part of each payment if you are registered, or 30% if you are not, and pays it to HMRC as an advance towards your tax. That deduction ignores 2 things that reduce your real bill: your £12,570 Personal Allowance and your business expenses. When your tax return works out the true figure, the amount already taken is often more than the amount due.

How the refund is claimed

If you are a sole trader or a partner, the claim is made on your Self Assessment tax return. You report your full pay before deductions as income and the total taken by contractors as CIS deductions. HMRC works out your tax and National Insurance, takes off the deductions and pays back any difference. You can file from 6 April, as soon as the tax year has ended, and you do not need to wait until January.

Limited companies do it differently. A company sets its CIS deductions against its monthly PAYE bill through its payroll submissions, and claims any balance after the tax year ends.

Key point: keep every monthly payment and deduction statement your contractors give you. They are the evidence for the refund, and a missing statement is the most common reason a claim is delayed.

What you can claim against CIS income

  • Tools, equipment and their repair
  • Protective clothing and safety boots
  • Travel to temporary sites, at 55p a mile for the first 10,000 business miles and 25p after that for 2026/27, or actual vehicle costs
  • Public liability insurance
  • Phone, and accountancy fees
  • Materials you paid for that were not reimbursed
Example

Dawid earns £38,000 in labour payments and has £7,600 deducted at 20%. He has £3,200 of expenses and drives 9,000 business miles, worth £4,950. His profit is £29,850. Income Tax is £3,456 and Class 4 National Insurance is £1,037, so £4,493 in total. His estimated refund is £7,600 less £4,493, which is £3,107.

What the calculator leaves out

Scottish tax rates, student loan repayments, payments on account already made and any tax you owe from earlier years, which HMRC will take from a refund first. For an exact figure we need your statements. Our guide on how to claim a CIS refund explains the full process.

Common questions

How much CIS tax will I get back?
It depends on your profit. As a rough guide, the refund is the CIS deducted less the Income Tax and Class 4 National Insurance due on your profit after expenses. The calculator above estimates it.
When can I claim my CIS refund?
From 6 April, once the tax year has ended, by filing your Self Assessment tax return. You do not have to wait until the 31 January deadline.
Is CIS deducted from materials?
No. The deduction applies to the labour part of the payment. The cost of materials you supplied should be excluded before the deduction is worked out.
What if I am on the 30% rate?
You are being treated as unregistered. Register for CIS to move to 20%. The extra tax already taken still counts towards your bill and comes back through your tax return if you have overpaid.
Can a limited company claim a CIS refund through its tax return?
No. A company offsets CIS deductions against its PAYE bill through payroll, and claims any remaining balance after the tax year ends. GOV.UK warns against using the Corporation Tax return for this.

Checked against GOV.UK on 10 November 2026: CIS subcontractors: pay tax and claim back deductions, What you must do as a CIS subcontractor, Simplified expenses: vehicles.

About the author

Hammad Rasool MAAT is an AAT licensed accountant based in Bolton. TaxTune Accountants looks after sole traders, landlords, contractors and limited companies in Bolton, Wigan, Bury, Salford, Oldham, Stockport and Manchester, and online across the UK.