| 2RUVIA Ltd | Leeds | 2025 |
| 2S Constructions Ltd | London | 2021 |
| 2S Interiors Limited | London | 2011 |
| 2S Projects Ltd | Paignton | 2025 |
| 2SAFE Electrics Ltd | Barking | 2025 |
| 2SALS Limited | Warrington | 2023 |
| 2SAPRO Ltd | Birmingham | 2022 |
| 2SH Developments Limited | Thurstonland | 2020 |
| 2SL Investments Ltd | Sutton | 2021 |
| 2SN Ltd | London | 2018 |
| 2SOL Limited | Sheffield | 2010 |
| 2SPC Mansfield Ltd | Milton Keynes | 2022 |
| 2SS Contractors Ltd | Cheltenham | 2011 |
| 2T Construction Ltd | Banbury | 2024 |
| 2T Scaffolding Limited | Edinburgh | 2012 |
| 2TECH Installations Ltd | Burnley | 2026 |
| 2TONE Scaffolding Limited | Rochester | 2016 |
| 2V Contracts Ltd | West Horndon | 2025 |
| 2V Projects Ltd | London | 2022 |
| 2W Homes Limited | Worcester | 2020 |
| 2W Solutions Ltd. | Lincoln | 2015 |
| 2WAYS Property Limited | Torquay | 2023 |
| 2WENTY47 Limited | Egham | 2008 |
| 2X Construction Ltd | Paisley | 2015 |
| 2X2 Construction Ltd | Ammanford | 2022 |
| 2X7 Ltd | Chichester | 2018 |
| 2XM Developments Limited | Exeter | 2024 |
| 2XR Ltd | Colchester | 2022 |
| 3 a Electrical Ltd | London | 2017 |
| 3 - GEN Ltd | Rochester | 2023 |
| 3 Alarms Limited | County Durham | 2005 |
| 3 Arrows Servicing Limited | Uttoxeter | 2018 |
| 3 Beagles Development Ltd | Frodsham | 2025 |
| 3 Bevis Green Limited | Birmingham | 2018 |
| 3 Bohemia Road Ltd | London | 2026 |
| 3 Brix Ltd | London | 2023 |
| 3 Brothers Builders Ltd | Leicester | 2026 |
| 3 Brothers Fencing@Landscaping Ltd | Woking | 2025 |
| 3 Brothers Flooring Ltd | Watford | 2023 |
| 3 Brothers Roofing Ltd | Staines-Upon-Thames | 2019 |
| 3 Build Construction Ltd | London | 2021 |
| 3 C Excavation Limited | Morpeth | 2022 |
| 3 C Investments Limited | Norfolk | 1987 |
| 3 C Services Limited | Morpeth | 2017 |
| 3 C'S Construction Services Ltd | London | 2004 |
| 3 Celts Limited | Cwmbran | 2019 |
| 3 Construction Limited | Antrim | 2024 |
| 3 Construction Services Ltd | Bellshill | 2021 |
| 3 Consult Limited | Cardiff | 2022 |
| 3 Cord Services Limited | Carmarthen | 2024 |
| 3 Core Construction Ltd | Nottingham | 2023 |
| 3 Core Electrical & Security Limited | Whitstable | 2007 |
| 3 Core Electrical Engineering Limited | Hull | 2010 |
| 3 Core Electrical Limited | Berwick-Upon-Tweed | 2010 |
| 3 Core Sparkies Ltd | Derby | 2025 |
| 3 Counties (Sandhurst) Ltd | Camberley | 2008 |
| 3 Counties Building Services Limited | Biggleswade | 2007 |
| 3 Counties Civil Engineering Limited | Southampton | 2000 |
| 3 Counties Cleaning Limited | Bournemouth | 2002 |
| 3 Counties Eco Heating Ltd | Farnham | 2023 |
| 3 Counties Electrical & Hvac Limited | Haslemere | 2024 |
| 3 Counties Enrg Ltd | Gloucester | 2025 |
| 3 Counties Garage Doors Ltd | Grantham | 2020 |
| 3 Counties Heating & Plumbing Ltd | Bedford | 2023 |
| 3 Counties Home Improvements (JM) Ltd | Spalding | 2025 |
| 3 Counties Mini Crane Hire Ltd | Aylesbury | 2023 |
| 3 Counties Roofing and Building Limited | London | 2022 |
| 3 Counties Surfacing Ltd | Spalding | 2022 |
| 3 Crowns Interiors Ltd | Hull | 2023 |
| 3 Crowns Property & Maintenance Contractors Ltd | Leeds | 2021 |
| 3 D Construction (UK) Limited | Church Lawton | 2003 |
| 3 D Decor Limited | Ilkeston | 1990 |
| 3 D Elis Construct Ltd | Dagenham | 2018 |
| 3 Degrees of Development Ltd | Altrincham | 2022 |
| 3 Delta Design & Construction Ltd | Loughton | 2014 |
| 3 Dimensions Limited | Cambridge | 2002 |
| 3 Dots ENG Ltd | London | 2021 |
| 3 ED Glasgow Limited | Edinburgh | 1998 |
| 3 ED Holdings Limited | Edinburgh | 1998 |
| 3 ED Sisterco Limited | Edinburgh | 2007 |
| 3 Education Limited | Aylesbury | 2009 |
| 3 Electrical Ltd | Leicester | 2013 |
| 3 Enterprise Limited | Edgware | 2010 |
| 3 Flow Limited | Manchester | 2017 |
| 3 Futures Developments Ltd | Southampton | 2020 |
| 3 Futures Ltd | Southampton | 2019 |
| 3 Gables Building Contractors Limited | Leigh On Sea | 2015 |
| 3 GEN Electrical (NW) Limited | Wigan | 2025 |
| 3 H & a Ltd | London | 2023 |
| 3 HT Property Services Ltd | Chesterfield | 2025 |
| 3 Interior Contracts Limited | Newry | 2009 |
| 3 Investments 3 Limited | Sidcup | 2023 |
| 3 J Flooring Ltd | Chatham | 2017 |
| 3 Jays Services Ltd | Newport | 2022 |
| 3 JS Builders Limited | Stourbridge | 2025 |
| 3 K Rail Construction Limited | Rochester | 2017 |
| 3 Kings Property Services Ltd | Birmingham | 2026 |
| 3 Knights (Management) Limited | Middlesex | 2001 |
| 3 KY Developments Ltd | Covent Garden | 2019 |
| 3 M Carpentry Limited | Melksham | 2018 |