CIS and development finance: Why the recent guidance changes matter 

The Construction Industry Scheme  (CIS) has long been a feature of the tax landscape for those working in and around the built environment, but it has rarely troubled conventional real estate finance arrangements. That position was tested sharply in May 2026. A change to HMRC’s internal guidance, followed swiftly by a further revision in June, has prompted a closer examination of where the boundaries of the CIS regime now sit and what that means for lenders, investors, and development finance professionals.

The story is still developing, but the practical implications are already worth understanding clearly.

What the Construction Industry Scheme does

The CIS is a withholding tax framework that applies to payments made by contractors to subcontractors for construction operations. Where it applies, contractors are required to verify their subcontractors with HMRC and make deductions from payments at source, either at the standard rate of 20% for registered subcontractors or at 30% where a subcontractor is unregistered. Those deductions are then accounted for to HMRC and offset against the subcontractor’s tax liability.

The scheme carries real administrative weight. Contractors must register with HMRC, file monthly returns, and maintain compliant payment processes. Failure to do so can result in penalties and, in certain circumstances, liability for amounts that should have been withheld. The April 2026 reforms introduced additional anti-avoidance measures within CIS payment chains, tightening the regime further for those who fall within its scope.

For most of the scheme’s history, the question of whether development lenders and investors could be drawn into it as contractors simply did not arise. The widely held view was that conventional financing arrangements fell outside the CIS because the party providing funds was not itself engaged in construction operations. It was a sensible and well-grounded position, and it underpinned a significant volume of development finance activity without meaningful challenge.

What changed in May 2026

On 5th May 2026, HMRC updated its internal guidance to state that the CIS may apply where a contract funds construction operations, even where the party providing those funds is not a construction business. This wording departed from the settled understanding of the scheme’s reach and generated immediate concern across the development finance market.

The concern was understandable. If a development loan could constitute a contract funding construction operations, then lenders under such facilities might find themselves treated as contractors within the CIS framework, with their borrowers characterised as subcontractors. The practical consequences would be significant: registration obligations, monthly filing requirements, additional HMRC scrutiny, and potential exposure under the April 2026 anti-avoidance provisions. For borrowers, the prospect of CIS withholdings being applied to loan drawdowns raised serious cash flow concerns, particularly where development budgets are tightly structured.

A further question was raised at the time about retrospective liability. The concern among practitioners was whether lenders who had made drawdown payments without CIS deductions might face penalties for historic non-compliance if HMRC were to take the view that such arrangements had always been within scope. It is important to note that HMRC did not suggest retrospective enforcement was a likely or intended outcome; this was a perceived risk arising from the ambiguity of the May guidance rather than a stated enforcement priority. Nevertheless, it contributed to a period of genuine uncertainty in the market while the position remained unclear.

The June 2026 revision and what it resolves

On 4 June 2026, HMRC updated its guidance to state expressly that pure financing arrangements, including lending, providing finance, and grant funding, fall outside the scope of the CIS. For lenders operating conventional development finance facilities, this is a welcome and important clarification. The fundamental position that straightforward loan arrangements are not caught by the scheme has been confirmed.

That confirmation matters, and it should alleviate the immediate anxiety that followed the May update for the majority of the market. The concern about withholdings on standard drawdown payments, and the associated question of historic exposure, recedes considerably in light of the June position.

What the June revision does not resolve, however, is the position of lenders, institutional funds, and investors whose arrangements involve an element of involvement in, or oversight of, how a development is carried out. For those parties, the question of whether their arrangements fall within the exemption is less clear, and the May guidance has, if nothing else, signalled that HMRC is prepared to examine the substance of funding structures with greater scrutiny than the market may previously have anticipated.

Where the uncertainty remains

Development finance arrangements vary considerably in their terms. Many go well beyond a simple loan and repayment structure. Monitoring rights, step-in provisions, consent requirements before key construction milestones are reached, and approval mechanisms over the appointment of contractors or the procurement of materials are all features that appear with some regularity in sophisticated development facilities. So too does a degree of profit participation or commercial co-investment that has a character distinct from pure lending.

HMRC has not yet published detailed examples of the features that would or would not take an arrangement outside the exemption, and it would be premature to treat any particular provision as definitively determinative. What can be said with reasonable confidence is that the substance of an arrangement is likely to matter more than its label, and that features which give a funder a material say in the conduct of construction activity may be more susceptible to scrutiny than those which simply protect the lender’s security or financial position. Whether and how HMRC will draw those distinctions in practice remains to be seen, but the direction of travel in the May guidance suggested an appetite for a closer look at arrangements that do not fit neatly into the conventional lending model.

The April 2026 anti-avoidance measures add a further dimension for certain market participants. Those reforms were principally directed at CIS fraud within payment chains, but their interaction with financing arrangements that sit in uncertain territory between straightforward lending and more active involvement in development activity is a consideration that those advising on or structuring such transactions will want to keep in view.

How lenders and the market are likely to respond

The events of May and June 2026 are likely to prompt a period of considered review among lenders, institutional funders, and their advisers, even where immediate compliance risk has been resolved by the June clarification. For many, the natural starting point will be an audit of existing facility agreements and monitoring arrangements to assess whether their terms could, on a realistic analysis, be characterised as involving something more than conventional financing. That process is not simply a compliance exercise; it is also an opportunity to document the basis on which facilities have been structured and to address any ambiguities before they become points of difficulty.

For new transactions, it seems probable that lenders and their solicitors will pay closer attention to the drafting of oversight and consent provisions than may previously have been the norm. There is a meaningful difference, from a CIS perspective, between a lender whose monitoring arrangements are directed at protecting its security and one whose consent rights extend to active involvement in how construction work is procured and carried out. Getting that distinction into the documentation clearly, and ensuring it is reflected in how arrangements operate in practice, is likely to become a more routine consideration in development finance negotiations.

Institutional funders and investors whose structures involve a greater degree of commercial participation in a development may seek contractual protections against unexpected CIS exposure as a condition of entering into new arrangements. That could mean indemnity provisions, representations about the nature of the arrangement, or agreed procedures for dealing with CIS obligations if it were determined that they applied. Lenders may also look more carefully at the terms on which step-in rights and development oversight provisions are framed, both to manage their own risk and to provide greater certainty to borrowers about the circumstances in which those rights would be exercised.

The effect, over time, may be a modest but discernible shift in how development finance documents address the boundary between lending and operational involvement. That shift will be driven not by any single authoritative ruling on the CIS position of development funders, but by a market appetite for greater contractual clarity in an area where the regulatory boundaries have turned out to be less settled than they appeared.

A lesson about substance over structure

The episode that unfolded between May and June 2026 carries a broader lesson that extends beyond the CIS itself. It demonstrates, with some clarity, that HMRC is willing to look past the legal form of a funding arrangement and consider its commercial substance. The May guidance made no distinction between a lender and a construction business based on how the parties described themselves or structured their documentation; it was the nature and effect of the arrangement that was treated as potentially determinative.

The June clarification confirms that pure financing sits outside the regime. But the word ‘pure’ is doing significant work in that formulation, and the question of what takes an arrangement beyond it has not been answered. For those operating in the development finance market, the lesson is that tax regimes which have long seemed comfortably remote can, with a revision of guidance, become immediately relevant. The most effective response is not to assume that the label applied to a transaction will be sufficient protection, but to ensure that its substance and its documentation are genuinely aligned.

If you would like to discuss how the CIS guidance changes may affect your financing arrangements or development transactions, our commercial property team would be glad to help.