T IRC v Barclay Curle & Co Ltd is one of the key cases when considering how far the definition of plant can extend. It is often referenced in more complex claims, particularly where assets are large, fixed or built into the land, and where the line between structure and apparatus is less obvious.
The case concerned a dry dock used in shipbuilding. HMRC argued that it was simply a structure, part of the setting in which the trade was carried on. The Court disagreed.
The dry dock was treated as plant because of the role it performed in the trade. It raised and lowered ships for repair, performing a direct function within the business. In reaching that conclusion, the Court looked at the dock as a single functional unit, including the excavation and concrete lining. Those elements were not treated in isolation, but were accepted as forming part of the apparatus itself.
That point is key. The fact an asset is large, fixed or structural does not prevent it from being plant. What matters is whether it is functioning as part of the trade.
But the boundary is still there. Not everything built into the land will qualify. Assets that simply store, contain or provide the environment for the trade will often fall on the setting side of the line, even where they are essential.
The analysis comes back to function. Is the asset doing something in the trade, or is it simply housing it?
In practical terms, this is where claims are won or lost. Infrastructure and industrial assets are not automatically excluded, but they do require careful analysis of how they operate in reality and how the asset performs within the wider system.
This approach continues to be reflected in later case law, including Gunfleet Sands case, where the courts again returned to the underlying function of assets and their relationship to the trade when determining whether expenditure falls within the capital allowances regime.
Barclay Curle is often relied on to support claims involving complex or integrated assets, but it should not be read as a blanket extension of the definition of plant. Its value is in how it frames the analysis.
The takeaway is that classification turns on function, not form. Where an asset operates as part of the apparatus of the trade, even if it is structural in nature, there may be scope. Where it does not, the claim will fall away.
