If your property business has crossed the £3 million construction-spend threshold over the last twelve months, or if you have taken on a refurb project as a property developer, you are now a contractor under the Construction Industry Scheme. That means before you pay any subcontractor for construction work, you have to verify them with HMRC first. The verification result tells you which of three withholding rates to apply on the labour element of the payment: zero for a gross-payment subcontractor, twenty percent for a subcontractor registered for payment under deduction, or thirty percent for an unregistered subcontractor. Skip the verification step and HMRC can recover the under-deducted tax from you, with late-filing penalties on top.

This page sets out the verification step, when it applies to a property business, what HMRC actually does when you submit a verification request, what the three withholding states mean for the payment, and what happens if you find yourself on the wrong side of the penalty regime.

Do I Need to Verify? The Property-Business Decision Tree

Before walking through the verification mechanic, you need to know whether the regime applies to you at all. CIS is an income-tax-side withholding regime under FA 2004 Part 3. The verification obligation falls on contractors and deemed contractors. The property-business position breaks into three categories.

Pure residential individual landlords. If you are an individual letting one or several BTL properties for residential rent, with no construction-trading element and no large-scale capex programme, you are not a contractor in the construction industry under FA 2004 s.59(1)(k) and you do not hit the deemed-contractor threshold under s.59(1)(l). When you pay a builder for refurb work on your BTL, the builder accounts for their own tax on the income received; you have no withholding or verification obligation. CIS does not apply to you.

Property developers. If you trade in property (spec building, refurb-and-resell, ground-up development, conversion projects), you are a mainstream contractor under FA 2004 s.59(1)(k) from the first payment to a subcontractor. There is no threshold to cross: the first payment triggers the regime. Verification, monthly CIS300 returns, withholding obligations, payment-and-deduction statements: the full set.

Property-investment companies, REITs, HMO operators, and large landlord groups. If you operate through a property-investment vehicle and your construction-related spend (refurbs, capex, fit-outs, system installations) crosses the £3 million rolling-twelve-month threshold, you become a deemed contractor under FA 2004 s.59(1)(l). The threshold was introduced by Finance Act 2021, replacing the earlier "£1 million for three consecutive years" averaging test, in force from 6 April 2021. The rolling-twelve-month measurement means you can move into and out of deemed-contractor status period by period; once in, the full contractor obligations engage from the date you cross the threshold.

What Counts as "Construction Operations"?

FA 2004 s.74 and Schedule A1 define the perimeter of what HMRC treats as construction operations. The definition is broad and the property-business reader will find most of their refurb-and-development spend caught.

In scope: construction, alteration, repair, extension, dismantling, or demolition of any building, structure, or works (including roads, walls, foundations, drainage); installation of heating, lighting, ventilation, air-conditioning, plumbing, drainage, fire-protection, and security systems; painting and decoration of internal or external surfaces of any building or structure; the cleaning of the interior of any building in the course of construction, repair, or restoration; site preparation; landscaping work that forms part of the construction project.

Out of scope: professional services (architects, surveyors, valuers, consulting engineers, building surveyors) under the Schedule A1 carve-out for professional advisers; manufacture or delivery of materials where there is no installation element on site; routine cleaning of premises not in the course of construction or restoration; carpet fitting; signwriting and installation of artistic works; certain landscaping work standalone of construction; carpet fitting; certain plant and machinery installations where the works are not part of construction operations on the building.

The HMRC CIS Manual at CISR14000 onwards gives the operational boundary and is the working reference. For property businesses, the practical rule of thumb is that any refurb engaging trades on site is in scope; any pure professional or consultancy fee is out of scope; pure materials supplies (without installation) sit outside; mixed labour-and-materials supplies are in scope but with the materials element excluded from the deduction base.

How Does Verification Actually Work?

Once you are a contractor or deemed contractor, the verification step runs as follows.

Step 1: Register as a contractor. If you are not already CIS-registered as a contractor, register with HMRC (online via the Business Tax Account, or by phone). Registration produces a contractor PAYE scheme reference and gives you access to the CIS online portal.

Step 2: Gather the subcontractor's details. Before the first payment, ask the subcontractor for their full legal name, their Unique Tax Reference (UTR), and (for a sole trader) their National Insurance number, or (for a limited company) the company UTR and Companies House registered company number. For a partnership, you need the partnership UTR and the individual partners' UTRs.

Step 3: Submit the verification request to HMRC. Log into the HMRC CIS online service through your Business Tax Account, enter the subcontractor's details, and submit. Alternatively, use a commercial CIS software product (FreeAgent, Xero with its CIS module, Sage, Iris) that has the verification API integration. The CIS helpline route is available for low-volume contractors but is slower.

Step 4: Receive the verification result. HMRC's system checks the subcontractor against the CIS register and returns one of three answers: gross-payment status (no deduction); registered for payment under deduction (twenty percent withholding on the labour element); or unregistered (thirty percent withholding on the labour element). HMRC issues a verification reference, a V-number, which you record against the subcontractor.

Step 5: Apply the correct withholding rate to every payment for two years. The verification is valid for the contractor-subcontractor relationship for approximately two tax years. You quote the V-number on each monthly CIS300 return and apply the verification-result withholding rate to every payment in that period.

The Three Withholding States Under FA 2004 s.62

The CIS deduction is on the labour element only. The materials element is excluded under FA 2004 s.61(2) and reg 6 of SI 2005/2045. The labour-versus-materials split is therefore critical to the calculation, and the contractor needs an itemised invoice from the subcontractor that supports the split.

Gross-payment status (zero withholding). A subcontractor who has applied for and been granted gross-payment status under FA 2004 s.64 and Schedule 11 is paid gross. The subcontractor settles their own tax in the normal way. Gross-payment status is a privilege granted on three tests (turnover, compliance, business) and reviewed annually; many high-volume professional subcontractors hold it because the cash-flow benefit is substantial.

Registered for payment under deduction (twenty percent). A subcontractor who is CIS-registered but does not hold gross-payment status is paid net of a twenty percent deduction on the labour element. The deduction is paid to HMRC monthly by the contractor; the subcontractor credits the deduction against their year-end income-tax or corporation-tax liability.

Unregistered (thirty percent). A subcontractor who is not CIS-registered is paid net of a thirty percent deduction on the labour element. The higher rate reflects the friction cost of HMRC not having an established record for the subcontractor; the deduction is still credited to the subcontractor's eventual tax liability, but the cash-flow drag is greater. Many one-off subcontractors fall in this category, especially where the contractor has not pre-collected their UTR before payment.

What Is Gross-Payment Status and How Do You Get It?

FA 2004 s.64 and Schedule 11 set the three-test gate for a subcontractor to be granted gross-payment status.

The turnover test. A minimum net construction turnover in the qualifying period (typically the previous twelve months). The headline figures are around £30,000 per individual or per partner in a partnership, with separate (higher) thresholds for limited companies based on group turnover. The exact figures move and should be checked against the current FA 2004 s.64 and Schedule 11 text.

The compliance test. Timely tax returns, NIC returns, and tax payments over the qualifying period. HMRC takes a strict view: a single late filing or late payment in the qualifying period can disqualify the application. The compliance test is the most common single reason for gross-payment refusal.

The business test. The subcontractor must carry on a genuine construction business with UK trading premises (or a registered UK address that is operationally used) and a UK bank account. Off-shore arrangements or paper-thin substance typically fail this test.

HMRC reviews gross-payment status annually. Failure of any test, especially the compliance test, triggers downgrade to payment-under-deduction status. The leading case on the discretion to withdraw is J P Whitter (Water Well Engineers) Ltd v HMRC [2018] UKSC 31, in which the Supreme Court confirmed HMRC's broad discretion in withdrawing gross-payment status, with limited grounds for judicial-review-style challenge.

What If I Pay a Subcontractor Without Verifying?

The penalty pathway is steep. Three categories of exposure arise.

Recovery of the under-deducted tax. HMRC can recover the deduction that should have been made from the contractor under FA 2008 Schedule 41 and reg 13 of SI 2005/2045. The contractor is treated as if it had made the deduction. If the contractor cannot demonstrate that the subcontractor accounted for the income separately, the contractor effectively pays the tax twice (once via the recovered deduction, once via the cost of the original gross payment).

Late-filing and inaccuracy penalties. FA 2009 Schedule 55 imposes late-filing penalties on the monthly CIS300 returns that should have reflected the unverified deduction. The penalty escalates with persistence: £100 at one month late, £200 at two months, plus tax-geared penalties at six and twelve months. Schedule 56 imposes late-payment penalties on the unpaid deduction.

Loss of gross-payment status. Where the contractor itself holds gross-payment status as a subcontractor on its own contracts, repeated CIS compliance failures can trigger withdrawal of that status, with a substantial cash-flow consequence on the contractor's own income.

The cumulative cost of a single series of unverified payments can dwarf the value of the underlying contract. The operational rule of thumb across the property-investment-company and developer cohort is: verify everyone before paying anyone, no exceptions, no shortcuts.

Want this checked against your specific situation?

Drop your email and a one-line summary. We reply within 24 hours, no phone call needed.

The Monthly CIS300 Return and the Nil-Return Trap

FA 2004 s.70 and SI 2005/2045 require a CIS300 return for every tax month from registration until deregistration. The monthly tax cycle runs from the sixth of one month to the fifth of the next, with the return due by the nineteenth of the following month.

The trap is that the return is required even when no payments have been made in the month. A property-investment company that registers for CIS during a development period and then enters an inactive period (between projects, refurb cycle complete) often forgets the monthly nil-return obligation and accumulates penalty exposure unnoticed. The fix is either to file nil returns through the inactive period, or to deregister formally once contractor status is no longer needed.

The CIS300 return captures, for each subcontractor paid in the month: the subcontractor's name, UTR, gross amount paid, materials element, labour element, deduction calculated. The contractor pays the deductions to HMRC by the twenty-second of the month (electronic) or the nineteenth (paper). Late payment engages the FA 2009 Schedule 56 regime.

What If My Subcontractor's CIS Status Changes Mid-Project?

A verification result is generally valid for the contractor-subcontractor relationship for approximately two tax years. During that period the same V-number and the same withholding rate apply to every payment in the relationship. The contractor does not need to re-verify before each payment.

Where the subcontractor's status changes mid-relationship (typically a downgrade from gross-payment to payment-under-deduction following an HMRC review), HMRC notifies the contractor on the next CIS300 return cycle or by direct communication. The contractor adjusts the withholding from the notification date forward. Past payments at the previous rate are not retro-corrected.

Re-verification is required when the two-year window expires, when the contractor-subcontractor relationship lapses and resumes (a gap of more than several months between projects), or when HMRC specifically requests it. Contractors who use commercial CIS software can configure automatic re-verification triggers based on the latest payment date.

How Does CIS Interact with the VAT Domestic Reverse Charge for Construction?

CIS and the VAT domestic reverse charge are two parallel regimes that operate on different bases but trigger together on the same payment to a CIS-registered subcontractor for standard-rated construction work. The contractor needs to operationalise both, in parallel.

CIS operates on the income-tax side: the contractor withholds the CIS deduction on the labour element and remits it to HMRC monthly via the CIS300 return. The materials element is excluded from the CIS deduction base.

The VAT domestic reverse charge operates on the VAT side: the subcontractor invoices the contractor without VAT (subject to specific reverse-charge wording on the invoice); the contractor accounts for the output VAT on its own VAT return and recovers the input VAT under the normal partial-exemption rules. The materials element is included in the VAT base.

For a payment to a CIS-registered subcontractor for standard-rated construction work, both regimes engage: CIS withholding on labour at the verification rate, and reverse-charge VAT on the full labour-plus-materials value. Our domestic reverse charge page covers the VAT-side mechanics in detail; for the cost-treatment angle on refurb spend see our landlord allowable expenses page.

Authorities Cited