Construction Has the Most Insolvencies of Any UK Sector. Here's Why Subbies Are Always Last in the Queue.

These are not abstract numbers. Every one of those failures represents unpaid subbies, missing retentions, abandoned sites, and broken supply chains. And the pattern is always the same: specialists and subcontractors bear the brunt, and they find out last.

Why Margins Are So Thin They Cannot Absorb Shocks

Main contractors on large public and residential schemes typically operate on net margins of 1–3%. That has been the industry norm for decades, driven by competitive tendering, fixed-price contracts, and client-side procurement pressure. At those margins, a single delayed payment, a materials cost spike, or an unexpected defect rectification can tip a project from profit to loss.

The problem is compounded by the contractual structure. Main contractors are paid by clients on 30–60 day cycles. They pay subbies on 30–45 day cycles after that. The working capital gap is bridged by retention — money withheld from subbies until practical completion and the expiry of the defects liability period, sometimes two years later. That retention sits in the main contractor's account, effectively financing the wider business.

When a main contractor fails, that retention is gone. The subcontractor who completed their package perfectly, on time and on budget, ends up as an unsecured creditor chasing 2.5–5% of their contract value through an insolvency process that may take years to resolve — and which will, in all likelihood, return pennies in the pound.

The VAT Float Is Gone Too

Since March 2021, the domestic reverse charge has removed another buffer subbies relied on. Previously, you raised a VAT invoice, collected the tax from the main contractor, and used that float between invoice date and your quarterly return as working capital. Under reverse charge, the main contractor accounts for VAT directly. You never see that cash. For a subcontractor on a £2 million contract, the loss of that float can represent £80,000 to £100,000 of working capital that simply no longer exists.

The construction sector went into 2026 with higher energy and material costs than 2024, geopolitical uncertainty driving input price volatility, interest rates still elevated by historical standards, and a Building Safety Act creating legacy liability exposure that is now being priced into contractor group risk assessments. The reverse charge sits on top of all that. The cash squeeze on subbies has never been tighter.

The Cascade Nobody Talks About

What is less visible than the headline insolvency numbers is what happens to the supply chain in the weeks after a major failure. When a tier 1 enters administration, performance bonds get called. Bond providers respond slowly, or dispute the call, or tighten their capacity for future bonds across the sector. Sister companies of the failed entity face reputational pressure. Subbies who were owed money by the failed firm face their own working capital shortfall — which affects their ability to perform on their other projects.

The replacement contractor mobilised to take over the package inherits an incomplete evidence chain. Defects in the original work may not emerge for months. The programme impact extends far beyond the time needed to physically replace the failed package. On a London scheme with a tight critical path, that cascade can cost more than the original failure.

And RSM's national head of construction said it plainly: main contractors battling macro headwinds push costs and risks down the supply chain. The sector's undercapitalised subbies have little resilience against price increases and project delays. That is not an accident of the market. It is the structural logic of the procurement model.

What Would Actually Change Things

Retention reform has been discussed for decades and delivered precisely nothing. The government's consultation on a retention deposit scheme stalled. The industry's self-regulatory approach to prompt payment has produced selective compliance and creative accounting rather than genuine culture change.

What changes the position for subbies in practice is not legislative goodwill. It is commercial intelligence and supply chain diversification. Subbies who rely on one or two main contractors for the bulk of their revenue are exposed when those contractors hit trouble. Subbies who have a broader spread of clients, verified through a platform that provides genuine financial visibility, are not immune to market conditions — but they are resilient to individual contractor failure in a way that concentrated relationships never will be.

That is the commercial case for supply chain technology. Not just efficiency. Survivability.