It depends on your structure, and the difference is significant for cash flow. A sole trader or partner reclaims through Self Assessment: the deductions are credited against your tax bill, and because 20% of gross labour usually exceeds the tax actually due on the profit, most subcontractors end up owed a refund each year. Limited companies cannot do that. A company offsets CIS suffered against its own PAYE liabilities through the EPS each month, and only claims a repayment after the tax year end if a balance remains. This catches out subcontractors who incorporate: money that used to come back annually via your return now sits with HMRC until it can be offset, and a company with no payroll to offset against waits until April.