The top 25 UK engineering consultancies, 2026
The UK's biggest engineering, design, project-management and cost consultancies ranked by the turnover in their own filed Companies House accounts. Consultancies only — contractors, defence-services groups and architects have their own lists — with UK-registered global groups footnoted as such.
What the filings show
The two biggest engineering consultancies in Britain are owned by nobody you can buy shares in: employee-owned Mott MacDonald (£5.76B) and trust-owned Arup (£2.48B) — both UK-registered global groups whose filings include their international work. The ownership map below them is the story: 14 of the top 25 answer to Canadian, American, Australian or European parents. Britain designs the world's infrastructure with consultancies it mostly no longer owns.
Turner & Townsend's 8-month transition period (aligning its year-end with majority-owner CBRE) annualises to roughly £1.7B — the chip in the Accounts column marks it — and WSP UK's +15% shows the infrastructure cycle still running hot. The growth table — Binnies (+21%), Ridge (+13%), Gleeds Europe (+12%), Currie & Brown UK (+11%) — is energy transition and water-sector work made visible in fees.
The raw SIC data needed a machete: Babcock and QinetiQ (defence services), Formula 1 constructors, semiconductor design captives and the National Nuclear Laboratory all file under engineering consultancy codes. And one famous name failed a different test — Wood Group's UK filings are two years stale after its audit saga, so it sits in the can't-rank list rather than the table.
Top 25 engineering consultancies in the UK by filed turnover
Latest accounts filed as of August 2026 · refreshed monthly
| # | Firm | Turnover | YoY | Staff | Accounts |
|---|---|---|---|---|---|
| 01 | Turner & Townsend PM & cost Holdco for a construction consultancy Turner & Townsend Holdings Limited, consolidated — CBRE-majority-owned, global. | £5.76B | — | 23,380 | FY to Dec 2025 |
| 02 | Mott MacDonald Employee-owned engineering consultancy group Mott MacDonald Group Limited, consolidated — employee-owned and global; the UK is its largest market. Its MMB water JV is ranked in our construction list. | £2.48B | -1% | 18,765 | FY to Dec 2025 |
| 03 | Arup Arup Group Limited, the trust-owned global consolidation. | £2.16B | -2% | 16,930 | FY to Mar 2025 |
| 04 | AtkinsRéalis UK Engineering and design consultancy The former WS Atkins UK business, now Canadian-owned; files under a holding-company SIC. | £1.42B | +8% | 9,841 | FY to Dec 2024 |
| 05 | WSP UK Engineering and technical consulting firm UK entity of Canada’s WSP. | £1.10B | +11% | 8,856 | FY to Dec 2025 |
| 06 | AECOM UK Infrastructure and engineering consultancy AECOM Limited; sibling AECOM Infrastructure & Environment (£249M) files separately. | £771M | -1% | 4,144 | FY to Oct 2025 |
| 07 | Jacobs UK Engineering and technical services subsidiary UK entity of the US Jacobs group. | £764M | — | — | FY to Sept 2025 |
| 08 | Arcadis UK Engineering and environmental consultancy Arcadis Consulting (UK) Limited; the group’s separate UK staffing entity is excluded. | £477M | +6% | — | FY to Dec 2024 |
| 09 | Worley Europe energy engineering Engineering and technical consultancy UK-registered European arm of Australia’s Worley. | £400M | -16% | — | FY to Jun 2025 |
| 10 | Stantec UK Engineering and architectural consultancy Sibling Stantec Hydrock (£77M, the former Hydrock) files separately. | £304M | +3% | 2,848 | FY to Dec 2025 |
| 11 | Fugro GB geo-data Fugro GB (North) Marine — survey and geo-data. | £209M | -5% | 727 | FY to Dec 2024 |
| 12 | Ramboll UK UK arm of the Danish foundation-owned group. | £197M | +3% | 1,585 | FY to Dec 2024 |
| 13 | Frazer-Nash defence & systems KBR-owned systems and engineering consultancy. | £193M | -9% | 1,496 | FY to Dec 2025 |
| 14 | Buro Happold Buro Happold Limited, the group filer. | £188M | +9% | — | FY to Apr 2025 |
| 15 | Ridge PM & cost Ridge and Partners LLP, consolidated. | £136M | +13% | 1,174 | FY to Dec 2024 |
| 16 | Waterman Waterman Group plc, consolidated (CTI Engineering-owned). | £131M | -3% | 1,177 | FY to Dec 2024 |
| 17 | Expleo UK digital & QA Engineering and quality services. | £129M | +6% | 938 | FY to Dec 2024 |
| 18 | Binnies water RSK Group’s water consultancy. | £124M | +21% | 652 | FY to Apr 2025 |
| 19 | Hoare Lea building services (M&E) Hoare Lea LLP, consolidated — the UK’s largest independent M&E design practice. | £121M | — | 1,111 | FY to Sept 2025 |
| 20 | Sweco UK Sweco UK Holding Limited, consolidated. | £112M | -0% | 1,050 | FY to Dec 2024 |
| 21 | Currie & Brown UK PM & cost Part of Dar Group. | £95M | +11% | 610 | FY to Dec 2024 |
| 22 | Tony Gee civil & structural Tony Gee and Partners LLP, consolidated. | £57M | — | 620 | FY to Mar 2025 |
| 23 | Gleeds Europe PM & cost Gleeds Europe Holdings — the largest consolidated filer of the Gleeds partnership network. | £55M | +12% | 440 | FY to Dec 2024 |
| 24 | Cundall building services (M&E) Cundall Limited (formerly Cundall Johnston & Partners LLP). | £49M | +8% | 671 | FY to Jun 2025 |
| 25 | Pell Frischmann civil & structural | £49M | +3% | 584 | FY to Dec 2025 |
The firms we can't rank
Engineering's missing names are partnerships without consolidated filings — and one group whose accounts simply aren't current.
- Wood Group (UK) — UK filings run two years behind after the group’s audit delays — we won’t rank a 2022 number in 2026
- Mace Consult — consolidated within Mace Limited, ranked in our construction list
- Pick Everard — no consolidated filing with disclosed turnover surfaced in scope
- Curtins — files without disclosed turnover (medium-company regime)
- Gleeds (single figure) — a partnership network of regional filers; its largest consolidated holding is ranked
- COWI, Royal HaskoningDHV (UK) — UK entities file below scope or without disclosed turnover
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 an engineering consultancy. Design, engineering, project-management, cost and specialist technical consultancies — tagged by discipline. We exclude contractors (our construction list), defence-services and technology groups, architects (their own list), government laboratories, and corporate design captives.
Scope. UK-registered filings. For overseas-owned firms (AtkinsRéalis, WSP, AECOM, Jacobs, Arcadis…) that's the UK entity; for UK-registered global groups (Mott MacDonald, Arup, Turner & Townsend) the filed consolidation includes international work — the footnotes say which. AtkinsRéalis files under a holding-company SIC and the big M&E and civil LLPs carry no SIC at all; both would be invisible to a naive SIC query.
Cadence. Rebuilt monthly as new accounts land. Spot a consultancy we've missed or misread? Tell us — the methodology only works if it's challenged.
Quick answers
- What is the biggest engineering consultancy in the UK?
- Turner & Townsend — £5.76B in its latest filed group accounts with 23,380 staff, just ahead of Arup. Both are UK-registered global groups; the figures include their international work.
- Why isn't Babcock or QinetiQ on this list?
- They're defence services and technology groups, not design consultancies — different business, different list. Contractors (Balfour Beatty, Mace) and architects (Foster + Partners) are also ranked separately.
- Who owns Britain's engineering consultancies?
- Mostly not Britain: 14 of the top 25 are owned overseas — Canadian (AtkinsRéalis, WSP, Stantec), American (AECOM, Jacobs), Australian (Worley), Dutch (Arcadis), Danish (Ramboll), Swedish (Sweco), Japanese (Waterman). The big employee- and trust-owned exceptions, Mott MacDonald and Arup, happen to be the two biggest.
- Where is Wood Group?
- In the firms we can't rank: its UK filings run two years behind after the group's audit delays, and we won't rank a 2022 number in 2026. When current accounts land, it returns to the table automatically.