09/06/2026
From 6 April 2026, HMRC has new powers to penalise construction contractors for non-compliance committed by their subcontractors, even when the contractor wasn't directly involved.
If you engage subcontractors in your construction business, this changes the risk profile of your supply chain significantly.
The new rule applies when HMRC determines that a contractor knew or should have known that a payment, or a CIS deduction being claimed, was connected to deliberate non-compliance by another party. This is an objective test, so HMRC doesn't have to prove you knew. They only need to show that a reasonable business in your position should have recognised the risk.
Where HMRC finds the test is met, the consequences are significant. The business can be assessed for a CIS charge of 20% of the payment made, plus a penalty of 30% of that assessment. Gross payment status can be removed immediately, with a minimum five-year bar on re-applying. And penalties can be transferred to directors or officers personally where the behaviour is attributed to them.
For a contractor making £100,000 of subcontractor payments connected to non-compliance, that's a £20,000 CIS charge plus a £6,000 penalty, on top of losing gross status and potentially exposing the directors personally.
What this means in practice is that supply chain due diligence is no longer optional. HMRC expects contractors to understand who they're paying, to verify CIS registration and compliance status, and to respond appropriately where risks are identified.
The contractors most exposed under the new rule are those engaging subcontractors without a structured verification process. CIS checks done once at the start of a relationship and never refreshed are exactly the situations HMRC will be looking at.
If you engage subcontractors and don't have a documented process for ongoing CIS verification and supply chain review, the next step is sitting down with a construction-specialist finance team to put one in place before HMRC reviews your position.