Are you a contractor, a deemed contractor, or both?
Housebuilders operating in 2026/27 frequently occupy more than one position in the CIS framework at the same time, and misreading which category applies leads to registration failures and penalty risk.
A mainstream contractor is any business in the construction trade that pays subcontractors. A housebuilder building homes for sale is, unambiguously, in the construction trade. CIS registration is compulsory before the first subcontractor payment is made. The obligation does not depend on company size, annual turnover or the number of subcontractors engaged. The trigger is the first payment.
A deemed contractor is a different creature entirely. This label catches businesses that are not primarily in the construction trade but that spend more than £3 million on construction work in a rolling 12-month period. The GOV.UK guidance states the test this way: "your business does not do construction work but you have spent more than £3 million on construction in the 12 months since you made your first payment." A property developer that funds housebuilding through a special purpose vehicle, or a group company that commissions construction rather than carrying it out, can become a deemed contractor even though it is not running a building firm. Once the threshold is crossed, the full CIS contractor obligations apply.
Large housebuilder groups sometimes hold both statuses simultaneously, one group entity as the mainstream contractor running the build, another as a deemed contractor funding it. Each entity's CIS position is assessed separately.
| Entity type | CIS position | Trigger |
|---|---|---|
| Housebuilder building homes for sale | Mainstream contractor | First subcontractor payment |
| Developer funding construction via SPV | Potentially deemed contractor | Rolling 12-month spend exceeds £3m |
| Business commissioning occasional refurbishment | Not CIS-registered unless £3m threshold crossed | £3m deemed contractor threshold |
If you are uncertain whether your structure creates a deemed contractor obligation, our guide to deemed contractors explained sets out the rules in full.
Verifying 20 to 50 subcontractors each month
Before paying a subcontractor for the first time, a contractor must verify that subcontractor's CIS status with HMRC. HMRC returns one of three results: Gross Payment Status (0% deduction), registered (20%) or unregistered (30%). The verification result determines the deduction applied to the labour element of every subsequent payment.
For a housebuilder with a large and rotating subcontractor base, verification is an ongoing task rather than a one-off exercise. The HMRC online CIS verification service allows batch submission of multiple subcontractor details, and most payroll and accounting packages with CIS functionality incorporate the verification step. What changes from April 2026 is that re-verification is now part of the monthly due-diligence duty, not a first-contact formality.
The practical workflow for a housebuilder running payments each month should look like this:
- Before each payment run, re-verify every subcontractor through HMRC's online service or via CIS-capable software.
- Run a Companies House check on each subcontractor that holds GPS or is newly engaged to confirm it is a legitimately registered and active entity.
- Verify that the bank account name the subcontractor has provided matches the registered business name. A mismatch is an immediate due-diligence flag.
- Apply the deduction rate returned by HMRC to the labour element of the payment only. Materials are excluded from the deduction base.
Keeping a written record of each verification, the date, the result and the HMRC reference, is essential. HMRC can request this evidence during a compliance check and the GPS due-diligence defence collapses without it.
The April 2026 GPS anti-fraud rules: what housebuilders must now do
Finance Act 2026 (c. 11, Royal Assent 18 March 2026) introduces the most significant change to GPS since the scheme began. The key provisions, in force from 6 April 2026, are:
Immediate revocation without notice. HMRC can remove GPS from a subcontractor on the housebuilder's supply chain where the contractor "knew or should have known" about fraudulent connections. The "should have known" standard means that failing to carry out due diligence is itself grounds for GPS revocation. No fraudulent intent on the contractor's part is required.
Five-year reapplication ban. GPS removed on fraud grounds now carries a five-year ban on reapplication. For a subcontractor on 0% deduction earning £400,000 a year in labour income, that translates to roughly £80,000 a year in additional upfront deductions compared with holding GPS.
Knowledge-based penalties under FA 2004 ss.62A/62B. A contractor that makes a payment knowing, or having reason to know, that a connected party has deliberately failed to comply with CIS is liable to a penalty of 20% of the payment (s.62A). A CIS300 return made in such knowledge attracts a heavier charge: an amount equal to the whole sum the return treats as deducted and paid, that is 100% of the sums returned, with no percentage reduction (s.62B). The liability falls on the payer or return-maker. Where the payer is a company, officers can face personal liability under general HMRC officer-liability rules, but no fixed percentage attaches to that exposure.
Three-step due diligence. To meet the "should have known" standard, the contractor must, before each payment: re-verify CIS status with HMRC, run a Companies House legitimacy check, and verify bank account name against the registered business name. All three steps, all documented.
For a housebuilder paying 40 subcontractors in a month, this means 40 verification checks, 40 Companies House checks and 40 bank name confirmations, every payment run. Embedding this into payroll software or a structured spreadsheet process before each month's payment run is the practical solution. Our broader guide to CIS supply chain compliance and due diligence covers the anti-fraud framework in full.
Monthly CIS300 returns and nil returns for housebuilders
A contractor must file a CIS300 monthly return by the 19th of the following tax month. Tax months run to the 5th, so the return covering the period to 5 July is due by 19 July. Payment of deducted amounts to HMRC is due by the 22nd (electronic) or 19th (cheque).
For a housebuilder with a large subcontractor base, the CIS300 contains one line per subcontractor paid in the month: the subcontractor's name, UTR, the gross amount paid, the materials element, the deduction rate and the amount deducted. Software that populates the return directly from the payment records eliminates the manual step and reduces the risk of arithmetic errors.
The nil return obligation, removed in 2015, was reinstated from 6 April 2026. Where a housebuilder makes no payments to subcontractors in a given tax month, it must still file a CIS300 nil return by the 19th, or pre-notify HMRC of inactivity. This catches winter shutdown periods and site-pause months. Missing a nil return triggers the same penalty ladder as a substantive return:
| Lateness | Penalty |
|---|---|
| 1 day late | £100 |
| 2 months late | £200 |
| 6 months late | £300 or 5% of the CIS liability (whichever is higher) |
| 12 months late | £300 or 5% of the CIS liability (whichever is higher); up to £3,000 or 100% where information is withheld deliberately |
A housebuilder that suspends work between December and March and omits nil returns for those months can accumulate four penalties of £100 or more before the spring payment run begins. Full detail on the nil return obligation is in our guide to CIS nil returns explained.
Deduction statements: issuing to 20 or more subcontractors
After each payment a contractor must issue a payment and deduction statement to every subcontractor within 14 days of the payment. The statement must show: the contractor's name and UTR, the subcontractor's name and UTR, the gross amount paid, the materials element deducted from the base, the deduction rate applied and the amount deducted.
For a housebuilder paying 30 subcontractors in a single payment run on, say, 15 July, all 30 statements must be issued by 29 July. Subcontractors need these statements to complete their Self Assessment returns and claim any overpaid CIS at the year end. Issuing them late is a compliance failure, and it creates a downstream problem for each subcontractor's own tax position.
Most payroll and accounting software generates statements automatically at the point of payment. Where the payment run is managed manually, building a 14-day calendar prompt into the process avoids the common error of letting statements slip until month end.
Full guidance on the format and content of deduction statements, and the contractor's record-keeping obligations, is in our guide to CIS for contractors: monthly responsibilities.
VAT domestic reverse charge and new-build housebuilding
The VAT domestic reverse charge (DRC) for construction services has been in force since 1 March 2021. Under the DRC, the customer accounts for the VAT to HMRC rather than the supplier charging it in the normal way. The DRC applies when all five conditions are met, including that the supply must be standard-rated or reduced-rated.
New-build residential housing is zero-rated for VAT. Because the supply is zero-rated, the fifth condition is not met, and the DRC does not apply. A groundworks subcontractor invoicing a housebuilder for work on a new-build site charges VAT in the normal way (or is exempt if not VAT-registered) rather than applying the reverse charge.
CIS still applies to the same payments regardless of the VAT treatment. The absence of DRC on a new-build project does not affect the CIS deduction obligation at all. Contractors sometimes conflate these two regimes, assuming that if DRC does not apply, CIS might not either. The two are separate. Zero-rated VAT exempts a supply from DRC; it does not exempt it from CIS.
For construction work on mixed-use developments where some elements are not zero-rated, the DRC position requires careful analysis on a supply-by-supply basis. Our guide to the VAT reverse charge for construction covers the five conditions and end-user exceptions in full.
GPS for housebuilder subcontractors: what the turnover tests mean
Many of the subcontractors working on a housebuilder's sites hold Gross Payment Status, which means the housebuilder makes no CIS deduction on their labour payments. The GPS eligibility test for a subcontractor that is a limited company requires net annual CIS turnover of at least £30,000 per director or £100,000 in total. For a sole-trader subcontractor, the threshold is £30,000 net.
"Net" in this context means excluding VAT and the direct cost of materials, consistent with the §1 labour-only deduction base. A subcontractor with £120,000 of total invoices including £40,000 materials and £10,000 VAT has net CIS turnover of £70,000. Where that subcontractor operates as a company with two directors, the £30,000-per-director test is met on £70,000 total. All three GPS tests (business, turnover and compliance) must be passed.
From 6 April 2026, holding GPS depends not just on qualifying but on ongoing due diligence at the contractor level. A housebuilder that fails to re-verify or check the supply chain creates the risk of GPS being revoked for subcontractors whose records reveal a compliance failure the contractor should have spotted. For GPS holders on a large housebuilder's supply chain, the indirect risk of contractor-level due-diligence failure is a new exposure to plan for.
The CIS subcontractor verification guide explains the verification process, the results it produces, and how to handle edge cases where HMRC returns an unmatched status.