Every company Archive Partners tracks carries a UK SIC code — the five-digit classification each business files with Companies House to describe what it actually does. Pull the full spread across our 650 tracked companies and a pattern falls out that says more about the current shape of UK business activity than any single filing could.
Construction is the single largest bloc
Group the SIC codes by sector and construction-related activity is the biggest cluster we track: roughly 13% of our tracked companies carry at least one construction SIC code — split across development of building projects (SIC 41100), construction of commercial buildings (41201), construction of domestic buildings (41202), and other specialised construction activities (43999). No other sector comes close to that combined share.
That spread across four adjacent codes, rather than concentration in one, is itself a signal. It suggests a fragmented supply chain — developers, commercial contractors, domestic builders and specialist subcontractors each filing under their own slice of the process — rather than a handful of vertically integrated firms. For anyone doing vendor risk or supply chain mapping in the built environment, that fragmentation is the finding: a shock to one sub-code (say, a slowdown in domestic construction) doesn’t necessarily transmit cleanly to commercial or specialist contractors filed under a different code, even though a generic “construction sector” search would lump them together.
The single most common code isn’t a trade at all
Look at individual codes rather than sector clusters, and the most frequent single SIC in our data is 82990 — “other business support service activities n.e.c.” — at roughly 4.6% of tracked companies. Close behind is 64209, “activities of other holding companies n.e.c.”, at 4.3%.
Neither of those is a trade you can point to on a map. They’re the two codes companies reach for when their actual activity doesn’t fit a neater box — a holding structure sitting above an operating subsidiary, or a support-services function that spans admin, consulting and back-office work under one registration. Their combined prevalence (just under 9% of our tracked population) is a reminder that a meaningful slice of UK corporate structure is organisational rather than operational: companies that exist to hold, coordinate or service other companies, not to make or sell something directly. For due-diligence teams, that’s exactly the population where the SIC code alone tells you the least — you have to look at officer overlap and group structure to understand what the entity actually does.
What this means for anyone reading the data
If you’re benchmarking a company against its “peer set,” these numbers are a useful sanity check before you trust a single SIC code to define that peer set. A construction firm registered under 43999 is genuinely answering a different question than one under 41201, even though a casual read would file both under “construction.” And a company sitting under 64209 or 82990 may not have meaningful trading peers at all in the conventional sense — its real comparison set might be other holding vehicles in the same corporate group, not other companies in the same SIC.
Archive Partners recomputes these SIC-level aggregates daily from live UK iXBRL filings, so the shape of this distribution — not just the headline number — is the thing worth tracking over time. A sudden shift in the construction share, for instance, would show up here well before it shows up in quarterly sector statistics.
All figures are based on the 650 companies currently tracked across Archive Partners’ county profiles, aggregated from Companies House SIC registrations. Explore the taxonomy reports for live stability metrics by individual SIC code.