Construction Industry Scheme (CIS)
HMRC's scheme where contractors take tax off subcontractors' payments.
Contractors in construction deduct 20% (or 30% if the subcontractor isn't registered) from the labour part of a subcontractor's invoice and pass it to HMRC. The subcontractor gets credit for it against their own tax.
General information about UK rules as of October 2026, not tax or legal advice.