Ask a room of tipper and muckaway operators whether they are in construction and half will say they just drive trucks. HMRC disagrees, and the disagreement has a name: the Construction Industry Scheme. Haulage businesses that carry for construction projects - muckaway, aggregates delivery, plant movement tied to site work - regularly find themselves inside CIS, sometimes as the contractor, sometimes as the subcontractor, occasionally as both on the same job.
GOV.UK’s CIS page states the mechanics: under the Construction Industry Scheme, contractors deduct money from a subcontractor’s payments and pass it to HMRC. The deductions count as advance payments towards the subcontractor’s tax and National Insurance - withheld money, not extra tax, credited against the subcontractor’s eventual bill.
Contractors must register for the scheme. Subcontractors do not have to register - but the page warns that deductions are taken from their payments at a higher rate if they are not registered. Registration is optional in the way that paying less withholding is optional.
HMRC’s guidance on making deductions and paying subcontractors sets the rates. The CIS deduction rates are 20% for registered subcontractors, 30% for unregistered subcontractors, and 0% if the subcontractor has gross payment status - meaning no deductions are made from their payments at all.
Run the cash-flow arithmetic on a muckaway job paying £2,000 a week. Registered: £400 a week held back. Unregistered: £600. Gross payment status: nothing withheld and the full £2,000 lands. For a business living on weekly cash flow - fuel on Friday, wages on Friday - the difference between those lines is the difference between comfortable and overdrawn. Gross payment status is the prize: the whole payment arrives and you settle your own tax, but it has to be earned and applied for, and the guidance sets the conditions.
The scheme’s definition of contractor reaches further than builders. The GOV.UK page has a whole section on who counts as a contractor or subcontractor, and the register-if rule catches businesses that spend heavily on construction operations through subcontractors - not just construction firms. A haulage company that wins a muckaway contract and subcontracts the actual carting to other tipper owners may be a CIS contractor for those payments, with the duty to register, verify subcontractors and make deductions. The operator who thought they were “just subbing some trucks out” and never registered is holding a compliance problem, not a clever arrangement.
Monthly returns are part of the contractor’s life too: the page notes that registered contractors can sign in to CIS online to file monthly returns or to verify a subcontractor. Verification is how the deduction rate gets confirmed - 20%, 30% or gross - before money moves.
The page’s section on work covered by CIS lists the construction operations in scope, with exceptions. Whether pure haulage of materials counts turns on the detail of what the contract involves - haulage tied into construction operations sits differently from a simple delivery. This is exactly the kind of line that should be checked against the GOV.UK detail for your specific work rather than decided in the cab, because being wrong in either direction costs money: deductions you should not have suffered, or a registration duty you failed to meet.
The money withheld under CIS is not gone - it counts as advance payments towards your tax and National Insurance, which means it surfaces again when your tax for the year is worked out. The subcontractor’s discipline is keeping the deduction statements the contractor issues, because those statements are the evidence that the withheld money was actually passed to HMRC on your behalf. A year of muckaway work without a matching pile of statements is a reconciliation headache at filing time; a clean folder of them is a credit you can point to. Chasing missing statements in the month they should arrive is normal administration, not awkwardness - the contractor has a process for issuing them and you have a tax position that depends on them.
If your trucks touch construction work: establish whether you are contractor, subcontractor or both on each contract; register if the contractor test catches you; get verified and paid at the right rate as a subcontractor - registered at 20%, never drifting into 30% through an unregistered oversight; and look hard at gross payment status once the business qualifies. CIS done right is a cash-flow detail. Done wrong, it is a permanent leak.