How to claim a CIS tax refund.

Updated October 2026

First: are you likely to be owed a refund?

Possibly, if any of these are true:

• You've had 20% (or 30%) deducted from your pay by contractors
• You paid for tools, equipment, PPE, insurance or travel yourself
• You didn't work the whole year, or had gaps between jobs
• You haven't yet filed a Self Assessment return for the year

Step by step

1. Collect your CIS statements. Each contractor must give you a monthly statement showing what they paid and what they deducted. Ask for any that are missing.
2. Add up your gross payments and deductions for the tax year (6 April to 5 April).
3. Add up your allowable expenses — see the list below. Keep the receipts.
4. Work out your profit: income minus expenses.
5. File a Self Assessment return. Your deductions are entered as tax already paid. If they're more than your bill, HMRC repays the difference.

What you can usually claim

• Tools and equipment you bought for the job
• Work clothing and PPE
• Vehicle running costs, or mileage at HMRC's simplified rates
• Insurance, such as public liability
• Phone and other costs used for work
• Accountancy fees

Everyday clothes, meals out and anything you didn't use for the business are not allowable.

A worked example (2026/27 rates)

Say your gross CIS payments for the year were £30,000, all for labour. Your contractors deducted 20% — £6,000. You spent £4,000 on tools, PPE and travel, and you have no other income.

This is an illustration only — your own figures will differ. Try your own numbers in the tax calculator, then compare with what your contractors deducted.

Common mistakes

• Not filing because "the contractor already took the tax"
• Throwing away receipts and statements
• Claiming personal costs as expenses
• Waiting too long — claims usually have to be made within four years of the end of the tax year

Want it done for you? See our CIS service.

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