How do I verify a subcontractor with HMRC under CIS?

Verification means checking a subcontractor's CIS status with HMRC, either through your accounting/payroll software, HMRC's online CIS service, or by phone, before you pay them for the first time. HMRC will confirm whether to deduct 20%, 30%, or nothing at all if they hold gross payment status, and gives you a verification reference to keep for your records. You don't need to re-verify subcontractors you've paid within the current or previous two tax years, provided you've included them on a CIS return in that time.