The biggest construction companies in the UK, 2026

The top 50 UK contractors ranked by the turnover in their own filed Companies House accounts — not press releases or trade-survey returns. Contractors only: housebuilders are a different business and ranked separately, materials producers and one-project JVs are excluded, and where a group's UK arms file separately we say which entity is ranked.

£59.61B combined turnover, top 55 contractors
116,803 directly employed staff
21 contractors at £1B+ turnover

What the filings show

UK contracting has no Big Four — it has a long, flat top. Morgan Sindall leads at £5.02B, but 21 firms clear £1B and the gaps between them are small, which is exactly what you'd expect in an industry that wins work project by project on low single-digit margins. Note the staff column: several £1B+ contractors directly employ only a few hundred people — the workforce is subcontracted, and the filed headcount tells you who actually carries the delivery risk.

The growth is in the ground and the grid, not the skyline. Mott MacDonald Bentley (+43%), Barhale (+34%), John Sisk & Son (+32%), M.V. Kelly (+31%) top the growth table — groundworks, water and industrial-services specialists riding infrastructure spend — and the infrastructure and industrial services firms on this list (Amey, M Group, FM Conway, Network Plus among 10) bill £6.83B between them.

The casualty list is real: McLaughlin & Harvey (-30%), Carey Group (-22%), Costain (-16%), Ardmore (-14%) all shrank by more than 5% year on year, and ISG — a top-ten contractor two years ago — isn't on the list at all, having entered administration in September 2024. In a sector where the median margin is thinner than a percentage point, a shrinking top line is rarely just a slow year.

Top 50 construction companies in the UK by filed turnover

Latest accounts filed as of June 2026 · refreshed monthly

# Firm Turnover YoY Staff Accounts
01 Morgan Sindall Listed construction and regeneration group Morgan Sindall Group plc, consolidated — construction, infrastructure, fit out (Overbury), property services and urban regeneration. £5.02B FY to Dec 2025
02 Balfour Beatty International infrastructure and construction group Balfour Beatty Group Limited, the UK group. The listed parent’s global accounts (including its large US business) are roughly double this and are not ranked. £4.66B +9% FY to Dec 2025
03 Kier UK construction and infrastructure group Kier Group plc, consolidated. £4.08B +3% 6,000 FY to Jun 2025
04 Keller specialist (geotechnical) Listed geotechnical specialist contractor Keller Group plc, consolidated — the world’s largest geotechnical contractor; the majority of group revenue is earned overseas. £3.09B +3% 3,947 FY to Dec 2025
05 Mace Construction and project management firm Mace Limited, consolidated — construction and consultancy. £2.79B +18% 7,085 FY to Dec 2024
06 Wates Family-owned construction and property group Wates Group Limited, consolidated. £2.40B +10% 5,192 FY to Dec 2024
07 Laing O'Rourke Multinational engineering and construction group Laing O’Rourke plc, the Europe hub consolidation; the group’s Australian hub files separately. £2.16B -10% 6,363 FY to Mar 2025
08 Galliford Try Listed British construction group Galliford Try Holdings plc, consolidated. £1.88B +6% 4,296 FY to Jun 2025
09 Amey infrastructure services Infrastructure and engineering services group Amey UK Limited, consolidated — highways, rail and complex facilities. £1.85B +1% 10,393 FY to Dec 2024
10 M Group infrastructure services PE-backed infrastructure services group M Group Limited, consolidated — utilities, transport and telecom infrastructure services. £1.38B 11,037 10-mo period to Mar 2025
11 VolkerWessels UK Multidisciplinary engineering and construction contractor VolkerWessels UK Limited, consolidated (VolkerFitzpatrick, VolkerStevin, VolkerRail and siblings). £1.49B +4% 3,967 FY to Dec 2024
12 BAM (UK) Civil engineering and infrastructure contractor BAM Nuttall Limited, the civil-engineering arm; sibling BAM Construct & Ventures UK (£924M) files separately — Royal BAM publishes no single UK consolidation. £1.48B +8% 3,643 FY to Dec 2025
13 Bowmer + Kirkland Commercial construction and development group £1.37B +6% 2,252 FY to Aug 2025
14 Skanska UK Commercial construction and infrastructure contractor Skanska UK plc, the UK group of Sweden’s Skanska AB. £1.37B +8% 3,281 FY to Dec 2025
15 Vinci Construction UK UK construction and engineering contractor Vinci Construction UK Limited; sibling Vinci arms (Taylor Woodrow civils among them) file separately — no UK-wide Vinci consolidation is filed. £1.34B 2,821 FY to Dec 2024
16 J Murphy & Sons Civil engineering and construction contractor £1.26B -9% 4,060 FY to Dec 2024
17 Willmott Dixon Holding company for construction group Willmott Dixon Holdings Limited, consolidated. £1.16B -1% 1,921 FY to Dec 2024
18 McLaren Construction Commercial and residential building contractor £1.12B +21% 1,082 FY to Jul 2025
19 Graham Holdco for a construction group John Graham Holdings Limited, consolidated. £1.06B -6% 2,297 FY to Mar 2025
20 Costain Listed construction and engineering group Costain Group plc, consolidated. £1.05B -16% 3,049 FY to Dec 2025
21 Winvic Commercial construction contractor Winvic Group Limited, consolidated — the dominant UK shed/industrial builder. £1.02B +6% 587 FY to Jan 2025
22 Multiplex Specialised construction contractor Multiplex Construction Europe Limited, the UK arm of the Brookfield-owned group. £973M +25% 701 FY to Dec 2025
23 Sir Robert McAlpine Building and civil engineering contractor £946M +1% 1,630 FY to Oct 2025
24 Robertson Holding company for a construction group Robertson Group (Holdings) Limited, consolidated. £793M -4% 2,887 FY to Jun 2025
25 TClarke specialist (M&E) Mechanical and electrical engineering contractor TClarke Contracting Limited. £847M 760 15-mo period to Mar 2025
26 McAleer & Rushe Design and build construction contractor £628M +28% 415 FY to Dec 2025
27 John Sisk & Son Construction and civil engineering contractor The UK-registered contracting company of Ireland’s Sisk group. £625M +32% 767 FY to Dec 2024
28 McLaughlin & Harvey Construction and civil engineering group McLaughlin & Harvey Holdings Limited, consolidated. £612M -30% 834 FY to Jun 2025
29 FM Conway infrastructure services Highways and civil engineering contractor £608M +5% 2,332 FY to Mar 2025
30 Network Plus infrastructure services Utility and infrastructure services provider £585M +9% 2,423 FY to Mar 2025
31 Tilbury Douglas Building and civil engineering contractor Tilbury Douglas Construction Limited; a sibling engineering company (£111M) files separately. £581M +12% 1,041 FY to Dec 2025
32 Altrad Services industrial services Industrial and infrastructure support services £551M +13% FY to Aug 2025
33 M.V. Kelly specialist (groundworks) Family-owned civil engineering contractor £504M +31% 327 FY to May 2025
34 Mott MacDonald Bentley specialist (water) Water sector civil engineering contractor A design-build joint venture; its co-owner J.N. Bentley (£510M) is not ranked separately to avoid double-counting. £503M +43% FY to Dec 2024
35 Ferrovial Construction UK Civil engineering and construction contractor The UK arm of Spain’s Ferrovial. £498M +2% 582 FY to Dec 2025
36 Severfield specialist (structural steel) Listed structural steelwork contractor Severfield plc, consolidated — the UK’s largest structural steelwork contractor. £451M -3% 1,964 FY to Mar 2025
37 Midgard Residential construction contractor The main-contracting company of the JRL Group. £580M 16-mo period to Apr 2025
38 MWH Treatment specialist (water) Water infrastructure construction contractor £431M +25% 785 FY to Apr 2025
39 Clancy Docwra infrastructure services Water infrastructure construction contractor The principal contracting company of the Clancy group. £429M +14% 1,858 FY to Mar 2025
40 Colas Rail infrastructure services Railway infrastructure and freight contractor Sibling Colas Limited (£258M, highways) files separately — no UK-wide Colas consolidation. £426M +5% 1,434 FY to Dec 2024
41 Bilfinger UK industrial services Industrial engineering and maintenance contractor £418M -0% 3,124 FY to Dec 2024
42 HG Construction Design and build main contractor £387M -0% 326 FY to Dec 2025
43 Bouygues UK UK construction and property developer The UK building arm of France’s Bouygues. £376M +15% 1,834 FY to Dec 2024
44 Caddick Construction Construction and civil engineering contractor £373M +5% 469 FY to Aug 2025
45 Keltbray specialist (demolition & enabling) Demolition and civil engineering subsidiary Keltbray Built Environment Limited. £364M +17% 601 FY to Oct 2024
46 OCU infrastructure services Utilities and energy infrastructure contractor OCU Utility Services Limited. £361M +19% 631 FY to Apr 2025
47 Glencar Privately-owned construction contractor £359M -10% 293 FY to Sept 2025
48 NG Bailey specialist (M&E) Engineering and infrastructure services provider £346M +11% 1,486 FY to Feb 2025
49 Ardmore Design and build main contractor Ardmore Group Limited, consolidated. £346M -14% 638 FY to Sept 2024
50 M & J Evans specialist (groundworks) Groundworks and civil engineering contractor £323M -3% 321 FY to Dec 2024

The next 5

Firms ranked 51–55

51 Octavius £323M +17% FY to Mar 2025
52 Carey Group specialist (groundworks) £303M -22% FY to Sept 2025
53 GMI Construction £233M +0% FY to Sept 2025
54 Barhale infrastructure services £228M +34% FY to Jun 2025
55 R.J. McLeod £303M 18-mo period to Apr 2025

The firms we can't rank

Construction's missing names are usually missing for a reason — and in this industry the reason is often the story.

How this list is built

Source. The latest annual accounts each firm filed at Companies House. Where a firm files consolidated group accounts, the group figure is used; the entity ranked is named under each firm. Where a firm filed a transition period longer or shorter than twelve months (flagged in the Accounts column), the table shows the filed figure but the firm is ranked on its annualised equivalent.

Who counts as a construction company. Building, civil-engineering and specialist contractors, plus infrastructure-services groups (tagged). We exclude housebuilders (a development business, ranked separately), materials producers and builders' merchants, design consultancies, facilities management, one-project joint ventures like Hinkley Point's Bylor (which would double-count their parents), and intra-group subsidiaries of ranked groups.

Scope. Rankings use each group's UK-registered filing. For UK arms of overseas groups (Skanska, BAM, Vinci, Ferrovial, Bouygues, Multiplex) that's the UK entity; for UK-headquartered groups with overseas work (Keller, Laing O'Rourke) the filed group figure includes it — the footnotes say which. Headcounts are hidden where a holding company disclosed only its own few staff rather than the group's.

Cadence. Rebuilt monthly as new accounts land. Spot a contractor we've missed or misread? Tell us — the methodology only works if it's challenged.

Quick answers

What is the biggest construction company in the UK?
Morgan Sindall is the UK's biggest construction company by filed turnover, reporting £5.02B in its latest accounts (FY to Dec 2025). Balfour Beatty's worldwide group is larger still, but most of its revenue is earned outside the UK — this list ranks its UK group filing.
Why aren't Barratt, Taylor Wimpey or Persimmon on this list?
They're housebuilders — developers that sell homes — rather than contractors that build for clients, and the two business models aren't comparable on turnover. Housebuilders are ranked separately; this list covers building, civil-engineering and specialist contractors.
How many UK construction companies turn over more than £1 billion?
21 contractors on this list filed (or annualise to) turnover above £1B. Roughly a quarter of the top 50 are UK arms of overseas groups — Skanska, BAM, Vinci, Ferrovial, Bouygues and Multiplex among them.
What happened to ISG?
ISG — previously a top-ten UK contractor — entered administration in September 2024, the industry's largest failure since Carillion. It appears in the "firms we can't rank" section rather than the table: a reminder that construction turnover is not the same thing as financial health.