| Rider Levett Bucknall | Birmingham, West Midlands, London | 49 | 21 |
| AECOM | London, Cardiff, Tower Hamlets | 12 | 137 |
| Faithful Gould | Epsom, Cardiff, London | 11 | 44 |
| Turner & Townsend Project Management | Leeds, City of London | 11 | 13 |
| Pennington Choices | Warrington, Norcott Brook, Cheshire West and Chester | 15 | 18 |
| Tetra TECH | Leeds | 13 | 13 |
| Calfordseaden | London, Bromley | 7 | 20 |
| PRP Architects | Surrey, Thames Ditton, London | 7 | 4 |
| Harmony Fire | Yeovil, Somerset, Chilthorne Domer | 10 | 10 |
| Global Hse Solutions | Nottingham, Nottinghamshire, Bingham | 10 | 10 |
| Ridge & Partners | Woodstock, Oxfordshire | 7 | 38 |
| Total Environmental Compliance | Corby, Northamptonshire | 7 | 4 |
| Arcadis | London, Belfast | 5 | 79 |
| Stace | Epping, Epping Forest, Essex | 5 | 7 |
| WSP | London, City of London | 8 | 132 |
| Integrated Water Services | Walsall | 7 | 9 |
| Airey Miller | Sevenoaks, Kent | 7 | 13 |
| SGS | Wirral, Ellesmere Port | 7 | 10 |
| Socotec | Burton upon Trent, Burton on Trent | 7 | 7 |
| A&E Fire & Security | Gloucester | 7 | 7 |
| Healthy Buildings Ireland | Reading, Newry | 7 | 7 |
| Rock Compliance | Nottingham | 7 | 7 |
| RG P | Leicester | 5 | 7 |
| Ove Arup & Partners | London | 4 | 72 |
| Savills | London, Westminster | 4 | 30 |
| Mace | London | 4 | 26 |
| Arcus Consulting | Sale, Trafford | 4 | 16 |
| WT Partnership | Croydon, London, Manchester | 4 | 5 |
| Couch Perry Wilkes | Solihull, London | 3 | 8 |
| Price & Myers | London | 3 | 5 |
| Si Sealy & Associates | Stockport | 3 | 3 |
| Pozzoni Architecture | Altrincham, Cheshire | 3 | 2 |
| Frank Rogers Building Contractor | Liverpool, Merseyside | 8 | 6 |
| Neo Property Solutions | Leeds, West Yorkshire | 7 | 10 |
| Ventro | Plymouth, Devon | 7 | 5 |
| Eyton Solutions | Wrexham | 6 | 6 |
| Openview Security Solutions | Romford | 5 | 33 |
| Santia Asbestos Management | Cardiff, Rhondda Cynon Taf | 5 | 5 |
| Breyer Group | Essex, Romford | 4 | 19 |
| HSL Compliance | Herefordshire, Ross on Wye | 4 | 18 |
| Frankham Consultancy Group | Kent, Sidcup | 4 | 14 |
| Tunstall Healthcare | Yorkshire, Whitley Bridge | 4 | 35 |
| Aaron Services | Essex, Basildon | 4 | 17 |
| Dodd Group Midlands | Shropshire, Telford | 4 | 11 |
| DFP Services | Durham, County Durham | 4 | 12 |
| Aspect Contracts | Essex, Basildon | 4 | 10 |
| Woods Building Services | Essex, Harlow | 4 | 9 |
| Testing Lab | South Yorkshire, Doncaster | 4 | 9 |
| Mchale Contracts & Plant Environmental | West Yorkshire, Bradford | 4 | 10 |
| Em1 | North Yorkshire, Northallerton | 4 | 8 |
| Life Environmental Services | Hertfordshire, Bishops Stortford | 4 | 7 |
| Ahr Building Consultancy | London, Huddersfield | 4 | 8 |
| Urban Environments | Kent, Sevenoaks | 4 | 7 |
| Crystal Electronics | Northants, Wellingborough | 4 | 7 |
| H2O Nationwide | Essex, Basildon | 4 | 6 |
| Midland Fire Security Services | Staffordshire, East Staffordshire | 4 | 5 |
| Erith Contractors | Kent, Erith | 4 | 5 |
| Appello Smart Living Solutions | Hampshire, Queensway | 4 | 4 |
| Bailey Partnership Consultants | Devon, Plymouth | 4 | 4 |
| Irwin M&E | County Armagh, Craigavon | 4 | 7 |
| Building Design Partnership | Manchester | 4 | 5 |
| Gully Howard Technical | Hampshire, Portsmouth | 4 | 5 |
| Rge Services | Essex, Chigwell | 4 | 5 |
| SMS Environmental | Oxfordshire, Didcot | 4 | 3 |
| WG Wigginton | Middlesex, Greenford | 4 | 4 |
| Countrywide Environmental Services | Staffordshire, Rugeley | 4 | 3 |
| NRT Building Services Group | Surrey, Reigate and Banstead | 4 | 3 |
| Asbestos Consultants Europe | Essex, Grays | 4 | 2 |
| Cablesheer Asbestos | Kent, Orpington | 4 | 2 |
| Electrical Compliance & Safety | Northamptonshire, Earlstrees Industrial Estate | 4 | 2 |
| Farrendale | Nottinghamshire, Sherwood Energy Village | 4 | 2 |
| Norwood Electrical | Derbyshire, North West Leicestershire | 4 | 2 |
| PA Group | Cheshire, Helsby | 4 | 2 |
| Reactive Integrated Services | Staffordshire, Burton on Trent | 4 | 2 |
| Trac Associates | Lancashire, Bury | 4 | 2 |
| Architectural Decorators | Kent, Sidcup | 4 | 4 |
| Arg Europe | Hertfordshire, Waltham Cross | 4 | 4 |
| Arvag | Kent, Swanley Village | 4 | 4 |
| BB7 Group | Kent, Rochester | 4 | 4 |
| Clarkes Environmental | North Yorkshire, Northallerton | 4 | 4 |
| Delco Safety | Surrey, Cheam | 4 | 4 |
| Devine Energy | Mid Lothian, Mid | 4 | 4 |
| Edp Health Safety & Environment Consultants | Cheshire, Helsby | 4 | 4 |
| Enviraz Scotland | Lanarkshire, Glasgow | 4 | 4 |
| Event Fire Solutions | Oxfordshire, Banbury | 4 | 4 |
| Fire Clear | Cambridgeshire, Huntingdon | 4 | 4 |
| G&L Consultancy | Somerset, Wellington | 4 | 4 |
| Greenfield Removals | Cheshire, Hyde | 4 | 4 |
| Hughes & Associates Property Services | Norfolk, Norwich | 4 | 4 |
| K & T Heating Services | Essex, Basildon | 4 | 4 |
| London Bridge Associates | Buckinghamshire, Gerrards Cross | 4 | 4 |
| Momentum 4 | Stirlingshire, Falkirk | 4 | 4 |
| Pier Contractors | Hertfordshire, St Albans | 4 | 4 |
| Reddish Vale Insulations | Lancashire, Oldham | 4 | 4 |
| See Rail | Essex, Ilford | 4 | 4 |
| Sureserve Fire & Electrical | Essex, Basildon | 4 | 4 |
| Total Fire Group | Lancashire, Milnrow | 4 | 4 |
| Trail Services | Kent, Northfleet | 4 | 4 |
| TS&B Contractors | Kent, Maidstone | 4 | 4 |
| TWC Services | Buckinghamshire, Buckingham | 4 | 4 |