Caught by CIS? What Property Businesses Need to Know About the Construction Industry Scheme
If you’re a landlord, developer, or property investor involved in any hands-on improvement work, the last thing you may expect is to be treated like a construction business. But under the Construction Industry Scheme (CIS), HMRC can — and does — classify unsuspecting property investors as “contractors.”
And that can lead to major tax headaches.
What is the CIS?
CIS is a tax scheme that requires contractors to deduct tax at source when paying subcontractors for construction work. It works like a lighter version of PAYE:
- 30% deduction if the subcontractor is unregistered
- 20% deduction for most registered subcontractors
- 0% if the subcontractor has gross payment status
Contractors are responsible for verifying subcontractor status and paying those deductions over to HMRC.
Why You Might Be in Scope (Even If You Don’t Think You Are)
You might assume CIS is only for big construction firms. But HMRC applies very broad definitions under the law. So if you:
- Renovate or convert property yourself
- Hire builders to carry out substantial refurbishments
- Create new dwellings from commercial units
- Or even divide up a portfolio with a lot of repair or building activity
…you could be treated as a contractor.
This is especially likely if your construction spend exceeds £3 million over the previous 12 months — at which point you become a “deemed contractor” under CIS. But some businesses have been pulled into the scheme even without hitting that threshold.
The Risk: CIS Deductions Missed? You Pay
If you’ve paid subcontractors without making the correct deductions under CIS, HMRC will treat you as liable — even if the subcontractor has already declared and paid tax on the income.
This could lead to unexpected liabilities stretching back several years, especially if you weren’t aware CIS applied to you. The tax can be significant — and it must be paid from your business’s own pocket.
Regulation 9: Your Potential Lifeline
Thankfully, Regulation 9 of the CIS rules offers some relief. HMRC may agree not to pursue you for CIS deductions if:
-
You made an honest mistake and took reasonable care (Condition A), or
-
The subcontractor has correctly declared the income and paid all their tax (Condition B)
You’ll need to work with HMRC to show either (or both) of these conditions apply.
Important: HMRC won’t tell you if the subcontractor has paid their tax due to privacy rules, so there’s a degree of trust involved.
Regulation 13: The Problem with Determinations
Here’s where it gets tricky. If HMRC issues a Regulation 13 determination — essentially their official calculation of what they say you owe — they’ve historically argued that this ends your right to any Regulation 9 reduction.
This position has recently been challenged in court. In the Beech Developments case, the Court of Appeal pushed back, arguing that fairness demands HMRC consider Regulation 9 relief even after a determination is made.
This is a big win for contractors — but you must act quickly once a Regulation 13 determination is issued to preserve your right to challenge.
Practical Steps: What to Do if You’re at Risk
- Check whether CIS applies to you. If you’ve paid subcontractors, especially for property renovations or development, review your obligations immediately.
- Get professional advice. This is a highly technical area, and the rules can be unforgiving.
- If HMRC gets in touch, engage early. Don’t wait — it’s easier to negotiate if you’re proactive.
- Keep excellent records. Show that you’ve taken care and made reasonable decisions at the time.
Conclusion: Don’t Get Caught Off Guard
CIS obligations can sneak up on landlords and property businesses, especially during busy periods of renovation or expansion. But the consequences of ignoring the scheme — or assuming it doesn’t apply — can be costly.
At Merranti, we help property investors, landlords, and developers navigate complex tax issues like CIS compliance. If you’re unsure about your position, or if you’ve had contact from HMRC about CIS, get in touch today for expert guidance.
