Does CIS Apply to You as a Property Investor or a Developer?

The Construction Industry Scheme, or CIS, decides whether tax must be deducted at source from payments for construction work. Whether it applies to you turns on a distinction that catches a lot of property businesses out: are you a property investor or a property developer? The two sound similar and often overlap in practice, but for CIS they sit on opposite sides of a line. Get it wrong and you either fail to operate a scheme you were required to run, or deduct tax you never needed to.

What CIS actually does

CIS is not a tax in itself; it is a deduction-at-source mechanism. Where it applies, a contractor paying a subcontractor for construction work must verify them with HMRC and deduct 20% (or 30% if unverified) from the labour element, paying it over to HMRC against the subcontractor's eventual tax bill. HMRC's guidance on the Construction Industry Scheme sets out who counts as a contractor and a subcontractor. The question for a property business is simply whether it falls on the contractor side at all.

Property developers: usually inside CIS

A property developer builds, converts or renovates property as a business, typically to sell or to create lettable space. Because that activity is construction carried out as a trade, a developer is a mainstream contractor for CIS and must operate the scheme on payments to the builders and trades it engages. This holds whether the developer is a company or an individual, and it applies from the first project rather than once some threshold is crossed. If your model is to spend money on construction to create or improve property for profit, assume CIS applies and plan for it from the outset.

Property investors: usually outside, until they are not

A property investor holds property to earn rent and capital growth rather than to develop and sell. A straightforward buy-to-let landlord commissioning ordinary repairs is generally not a contractor and does not operate CIS on those payments. But there are two ways an investor crosses the line. The first is becoming a deemed contractor: a business whose own construction spending exceeds £3 million in any rolling twelve-month period is pulled into CIS even where construction is not its trade, a rule aimed at large property owners and businesses with heavy build programmes. The second is when the work stops looking like maintenance and starts looking like development, such as a major refurbishment or conversion undertaken to create new units.

That second route is where the investor and developer labels blur. A landlord who gut-refurbishes a block to create flats for sale is, on that project, behaving as a developer, and the CIS obligation can follow the activity rather than the label you give yourself. Where a refurbishment is substantial, it is worth checking the position before the first payment to a trade, not after.

Why the line matters for your tax

The consequences run both ways. A developer or deemed contractor who fails to operate CIS faces penalties for late returns and unpaid deductions, plus the cost of deductions it should have made. An investor who needlessly operates CIS, or who has 30% deducted from its own payments as an unverified subcontractor, ties up cash with HMRC that it then has to reclaim. The distinction also interacts with how a property business is structured, which we cover in our guide to property development and SPV structuring.

Because the borderline cases, large refurbishments, mixed investor and developer activity, or crossing the deemed-contractor threshold, are exactly where mistakes get expensive, this is worth a professional view. The ICAEW maintains a useful overview of Construction Industry Scheme issues for the harder cases.

If you are not sure whether your property activity puts you inside CIS, or you have a refurbishment that might cross the line, our CIS rebate and compliance service can confirm your status and operate the scheme properly. Send us the details through the form on this page.