| 1 QT Development Limited | St. Andrews | 2022 |
| 1 Rede Place Limited | London | 2013 |
| 1 SAR Ltd | Maidstone | 2013 |
| 1 Scaffolding Ltd | Hove | 2012 |
| 1 Secure Ltd | Ashton Under Lyne | 2014 |
| 1 Solution Contracts Ltd | Swanscombe | 2023 |
| 1 South Drive Ltd | Croydon | 2022 |
| 1 SP Ltd | Muckamore | 2017 |
| 1 Sparky Ltd | Birmingham | 2023 |
| 1 SRY Limited | London | 2025 |
| 1 ST Mary's Terrace Limited | London | 2022 |
| 1 Stop Build Shop Ltd | Bracknell | 2025 |
| 1 Stop Building & Maintenance Uk-Uk Limited | Oldbury | 2022 |
| 1 Stop Glazing and Construction Ltd | Manchester | 2022 |
| 1 Stop Paving Yorkshire Limited | Leeds | 2024 |
| 1 Stop Renewables Installations Limited | Bridge Of Weir | 2012 |
| 1 Stop Renewables Wind Energy Ltd | Bridge Of Weir | 2010 |
| 1 Sycamore Square Ltd | Newcastle Upon Tyne | 2022 |
| 1 the Best UK Ltd | Barking | 2024 |
| 1 the Drive Developments Ltd | Wadhurst | 2023 |
| 1 to 1 Services Limited | Maldon | 1995 |
| 1 Tomswood Limited | Purfleet | 2018 |
| 1 Top Choice Ltd | West Midlands | 2022 |
| 1 Trafalgar Mews Management Company Limited | Woodford Green | 2011 |
| 1 Vernon Yard Limited | London | 2003 |
| 1 Wants IT Ltd | Colne | 2009 |
| 1 Way Tech Solutions Limited | London | 2024 |
| 1 Wisbech Road March Ltd | London | 2020 |
| 1& Limited | London | 2025 |
| 1-2 Call Drainage & Groundwork Limited | King'S Lynn | 2005 |
| 1-2 Hepscott Road Limited | London | 2015 |
| 1-2 Lincoln's Inn Fields | London | 2009 |
| 1-2-1 Building Solutions Ltd | Plymouth | 2018 |
| 1-2-1 Plumbing & Heating Limited | Chesterfield | 2014 |
| 1-3 Dixon Road Ltd | Bristol | 2020 |
| 1.21 Gigawatts Ltd | Weybridge | 2019 |
| 1.3.7 Developments Ltd | Burton Upon Trent | 2021 |
| 1.61 London Developments Ltd | Lancing | 2021 |
| 1.61 London Ltd | Lancing | 2010 |
| 1.61 London SJW 1 Limited | Lancing | 2024 |
| 1.61 London SJW Limited | Lancing | 2022 |
| 10 10 Salon Ltd | Bognor Regis | 2020 |
| 10 Brock Street Limited | London | 2010 |
| 10 Building Maintenance Ltd | Whyteleafe | 2021 |
| 10 Developments Ltd | Sandbach | 2025 |
| 10 Glen Property Development Limited | Ballymena | 2020 |
| 10 JS Limited | Leeds | 2020 |
| 10 March Limited | London | 2026 |
| 10 Market Square Developments Limited | Leytonstone | 2020 |
| 10 Minutes More Ltd | Nottingham | 2023 |
| 10 Property Services Limited | Swindon | 2011 |
| 10 ST. Bride Street Limited | Leatherhead | 1989 |
| 10 the Broadway Development Limited | Deal | 2015 |
| 10 the Broadway Freehold Management Limited | Deal | 2015 |
| 10 the Broadway Holdings Limited | Deal | 2015 |
| 10 Triton Street Limited | London | 2012 |
| 10 Woodhouse Street Limited | Stoke-On-Trent | 2012 |
| 10-10 Brickworks Ltd | Manchester | 2020 |
| 10-11 Clerkenwell Green Limited | Guildford | 2015 |
| 10-PROJECT Controls Ltd | Monmouth | 2018 |
| 10-TEN Construction and Engineering Ltd | Ammanford | 2019 |
| 10.7 Developments Ltd | Camberley | 2014 |
| 10/10 Construction Ltd | Feltham | 2020 |
| 10/10 Electrical Limited | Waltham Abbey | 2018 |
| 10/10 Services London Ltd | Borehamwood | 2024 |
| 10/TEN Construction Limited | Borehamwood | 2019 |
| 100 Golborne Road Limited | London | 2019 |
| 100 Effects Ltd | London | 2019 |
| 100 Global Resources Ltd | Cardiff | 2023 |
| 100 Global Ventures Ltd | London | 2022 |
| 100 HHR Limited | Westbourne | 2026 |
| 100 Keys Ltd | Cardiff | 2019 |
| 100 Percent Group Limited | Manchester | 2009 |
| 100 Trash Limited | London | 2012 |
| 100 Variants Ltd | Brentwood | 2015 |
| 100 Warwick Gardens Limited | Watford | 1995 |
| 100% Access Limited | Weston-Super-Mare | 2025 |
| 100% Construction & Renovation Limited | Cirencester | 2019 |
| 100% Heating and Plumbing Limited | Twickenham | 2019 |
| 100% Recycling Ltd | Chesterfield | 2011 |
| 100% Renewables Ltd | Weston Super Mare | 2023 |
| 100% Solar Energy Ltd | London | 2021 |
| 100% Tiling Limited | Elland | 2018 |
| 100%GAS Ltd | Warrington | 2024 |
| 100&KO Ltd | Romford | 2015 |
| 1000 Volts Ltd | London | 2017 |
| 100MM Limited | London | 2026 |
| 100YEARS Construction Ltd | London | 2021 |
| 101 Acoustics Ltd | Blaenau Ffestiniog | 2007 |
| 101 Acres Ltd | London | 2026 |
| 101 Cleveland Street JV Company Limited | London | 2019 |
| 101 Cleveland Street Midco 1 Limited | London | 2019 |
| 101 Cleveland Street Midco 2 Limited | London | 2019 |
| 101 Construction & Landscaping Ltd | High Wycombe | 2020 |
| 101 Construction Limited | Bradford | 2014 |
| 101 Developers Ltd | Leicester | 2018 |
| 101 Developments Limited | Ilkeston | 2009 |
| 101 Electrical Ltd | St. Neots | 2022 |
| 101 Engineering Solutions Ltd | Twickenham | 2016 |
| 101 Enterprises Ltd | Norwich | 2025 |