| PA Consulting Services | London, Westminster | 15 | 54 |
| Pfizer | Sandwich, Kent | 6 | 24 |
| Moderna Switzerland | Basel | 4 | 4 |
| Pricewaterhousecoopers | More London Riverside, Southwark, London | 3 | 75 |
| Aventis Pharma | Reading, Berkshire | 3 | 4 |
| Glaxosmithkline Biologicals | Rixensart | 3 | 3 |
| Sunamp | East Lothian, Macmerry, Tranent | 3 | 3 |
| Deloitte | London | 7 | 122 |
| Jacobs | London, Southwark | 3 | 62 |
| IBM | North Harbour | 3 | 34 |
| Ricardo AEA | Shoreham by Sea, Didcot | 3 | 22 |
| Pinsent Masons | London | 3 | 17 |
| Burges Salmon | Bristol, One Glass Wharf | 3 | 7 |
| Clifford Chance | London | 3 | 5 |
| Oxford University | Oxford | 3 | 6 |
| CP Pharmaceuticals | Wrexham | 3 | 3 |
| Aether | Oxford | 3 | 3 |
| Bioindustry Association | London | 3 | 3 |
| Gavi Alliance | Le Grand Saconnex | 3 | 3 |
| Novavax | Gaithersburg | 3 | 3 |
| Oxford Immunotec | Abingdon, Milton | 3 | 3 |
| Valneva SE | Saint Herblain | 3 | 3 |
| Veracity Consulting | Hythe, West Hythe | 3 | 3 |
| Mckinsey | London, Camden | 2 | 37 |
| Baringa Partners | London | 2 | 18 |
| RSK ADAS | Helsby, Helsby Cheshire | 2 | 18 |
| Efficio | London, Westminster | 2 | 5 |
| UK Centre for Ecology & Hydrology | Wallingford, Wallingford Oxfordshire | 2 | 13 |
| Element Energy | Cambridge, London | 2 | 3 |
| Astrazeneca | Cambridge | 2 | 3 |
| Forest Research Forestry Commission Research Agency | Farnham, Farnham Surrey | 2 | 2 |
| Foundry4 Consulting | London | 2 | 2 |
| Gluckman Consulting | Cobham, Cobham Surrey | 2 | 2 |
| Intelogy | Sunbury on Thames, Spelthorne | 2 | 2 |
| Rothamsted Research | Harpenden, Harpenden Herts | 2 | 2 |
| UK Centre for Ecology & Hydrology Ukceh | Wallingford, Wallingford Oxfordshire | 2 | 2 |
| National Nuclear Laboratory | Warrington | 6 | 7 |
| Mott Macdonald | Croydon | 5 | 60 |
| Visionist | Ringwood | 5 | 7 |
| PA Consulting | London | 4 | 4 |
| Triad Group | Godalming | 4 | 5 |
| Manning Gottlieb Omd Group | London | 4 | 4 |
| Vodafone | Newbury | 3 | 32 |
| Continental Product Engineering | Loddon | 3 | 4 |
| Pietro Fiorentini Spa | None | 3 | 4 |
| Roche Products | Welwyn Garden City | 2 | 14 |
| Oliver Wyman | London | 2 | 8 |
| Eon Energy Solutions | Coventry | 2 | 9 |
| Hippo Digital | Leeds | 2 | 7 |
| Veracity OSI | London | 2 | 6 |
| Arup | London | 2 | 79 |
| Cepa | London | 2 | 5 |
| Solirius | London | 2 | 12 |
| Environment Agency | Bristol | 2 | 3 |
| British Standards Institution | London | 2 | 3 |
| Warmworks Scotland | Edinburgh | 2 | 3 |
| Parity Projects | London | 2 | 2 |
| GL Industrial Services | Loughborough | 2 | 2 |
| Ovo Energy | Bristol | 2 | 2 |
| Adroc | Romford | 2 | 2 |
| Airfinity | London | 2 | 2 |
| Concept Equipment | Worthing | 2 | 2 |
| Databarracks | Wandsworth | 2 | 2 |
| Fivium Holdings | London | 2 | 2 |
| Fordway Solutions | Godalming | 2 | 2 |
| Icebreaker One | Epsom | 2 | 2 |
| Janssen Pharmaceutica NV | Beerse | 2 | 2 |
| Kaluza | Bristol | 2 | 2 |
| Kuehne Nagel | Feltham | 2 | 2 |
| Meatadataworks | Totnes | 2 | 2 |
| Offshore Renewable Energy Catapult | Blyth | 2 | 2 |
| Retrofitworks | London | 2 | 2 |
| Rina TECH | Leatherhead | 2 | 2 |
| Civica | London | 1 | 86 |
| AECOM | London | 1 | 137 |
| KPMG | London | 1 | 102 |
| Ove Arup & Partners | London | 1 | 72 |
| Specialist Computer Centres | West Midlands | 1 | 122 |
| Capgemini | London | 1 | 36 |
| Mazars | London | 1 | 27 |
| Methods Business & Digital Technology | London | 1 | 40 |
| IFF Research | London | 1 | 29 |
| CGI IT | London | 1 | 21 |
| Behavioural Insights | London | 1 | 13 |
| Boston Consulting Group | Westminster | 1 | 22 |
| TLT | Avon | 1 | 12 |
| Frontier Economics | London | 1 | 18 |
| Korn Ferry | London | 1 | 9 |
| Umi Commercial | Seaham | 1 | 12 |
| Jeremy Benn Associates | Craven | 1 | 8 |
| Investigo | London | 1 | 22 |
| Newton Europe | Vale of White Horse | 1 | 11 |
| Experis | Altrincham | 1 | 8 |
| Iron Mountain | London | 1 | 7 |
| Ashurst | Newry, Mourne and Down | 1 | 10 |
| ICF Consulting Services | London | 1 | 8 |
| Digital Accessibility Centre | Neath Port Talbot | 1 | 6 |
| Gowling WLG | West Midlands | 1 | 6 |
| Actica Consulting | Guildford | 1 | 15 |
| Smartsourcing | South Benfleet | 1 | 64 |