CIS takes 20% off your labour all year — usually more tax than you actually owe. Estimate what comes back after 5 April.
The 20% deduction ignores your personal allowance (£12,570 tax-free) and your expenses. All year you overpay; Self Assessment reconciles it and HMRC refunds the difference — commonly £1,500–£3,000 for a full year on the tools.
Every legitimate expense — tools, fuel, workwear, parking, phone, insurance — cuts your taxable profit and grows the refund by 26-42p per pound. No receipt, no claim: that is why keeping receipts all year matters more than anything your accountant does in April.
Your CIS statements and receipts are the evidence. Graftum Pocket keeps your worked days, CIS deductions and photographed receipts in one place — come April, you hand your accountant one clean PDF.
After the tax year ends on 5 April. File your Self Assessment early — refunds for early filers usually land within a few weeks.
The estimate still works — type the real amount deducted into the CIS box. Higher deductions usually mean a bigger refund, but register for CIS to get on 20% going forward.
No — it ignores other income, student loans, payments on account and Class 2 nuances. Treat it as a solid ballpark and let your accountant do the exact return.
Graftum Pocket logs your days, CIS deductions and every photographed receipt — then prints the tax-year statement your accountant needs.
Open Graftum Pocket — freeRough estimate for sole traders, 2025/26 rates. Not tax advice — your accountant's calculation is the one that counts.