| Alchemy Services and Media Limited | London | 2020 |
| Alchemy Services Limited | Glastonbury | 2006 |
| Alchemy Social Impact (UK) Limited | Cobham | 2025 |
| Alchemy Surfaces Limited | Harrogate | 2025 |
| Alchemy. PD Ltd | Peterborough | 2020 |
| Alchester Construction Limited | Bicester | 2016 |
| Alchmex International Construction Limited | London | 1976 |
| Alcis Group Ltd | London | 2023 |
| Alco Construction Ltd | Godalming | 2012 |
| Alco Contracts Limited | Wickford | 2013 |
| Alco Decorating Ltd | Godalming | 2024 |
| Alco Development Ltd | Godalming | 2024 |
| Alco Electrics Limited | Gloucester | 2022 |
| Alco Estates Limited | Sandilands Sutton On Sea | 1950 |
| Alco Facilities Management Ltd | Maldon | 2020 |
| Alco Interiors Limited | Wickford | 2013 |
| Alco Kitchens Ltd | Wickford | 2023 |
| Alco Landscapes Ltd | Waterlooville | 2025 |
| Alco Line M.G Ltd | Rotherham | 2023 |
| Alco Management Limited | Sidlesham, Chichester | 2007 |
| Alco Plastering & Building Services Ltd | Birmingham | 2025 |
| Alco Projects Limited | Wickford | 2025 |
| Alco RD Ltd | Hounslow | 2022 |
| Alco Roofing Limited | Bolton | 2015 |
| Alco Roofing South East Ltd | Godalming | 2024 |
| Alcock & Bailey Limited | Newcastle | 1986 |
| Alcock Construction Ltd | Stoke-On-Trent | 2025 |
| Alcock Fabrications Ltd | Cardiff | 2019 |
| Alcock Investments Limited | Cambridge | 1988 |
| Alcom Environmental Limited | Hemel Hempstead | 2024 |
| Alcomfix Ltd | Harrow | 2026 |
| Alcon Alarms Ltd | Wickford | 2024 |
| Alcon Builders Ltd | Norwich | 2025 |
| Alcon Construction Ltd | Port Talbot | 2025 |
| Alcon Flooring Limited | Huntingdon | 2009 |
| Alcon International Limited | Carshalton | 1986 |
| Alcon's Team Ltd | Southampton | 2023 |
| Alconbury 39 Ltd | London | 2023 |
| Alconex Infrastructure and Solutions Limited | Garforth | 2017 |
| Alconstruction Brickwork Ltd | Northampton | 2026 |
| Alcooper Ltd | Tyldesley | 2018 |
| Alcore Construction North East Limited | Aberdeen | 2015 |
| Alcorn Contracts Ltd | Cumnock | 2023 |
| Alcorn Glazing Ltd | Maidstone | 2016 |
| Alcosa Engineering Limited | Wymondham | 2002 |
| Alcott Insulations Ltd | Wirral | 2019 |
| Alcove Woodens Ltd | Hayes | 2022 |
| Alcra Joinery Ltd | Leven | 2020 |
| Alcram Electrical Ltd | Altrincham | 2013 |
| Alcris Builders Limited | Wirral | 2021 |
| Alcuin Homes (Bradford) Limited | York | 2015 |
| Alcuin Homes (Brighouse) Limited | Wakefield | 2014 |
| Alcuin Homes (Flawith) Limited | York | 2017 |
| Alcuin Homes (York) Limited | York | 2017 |
| Alcuin Homes (Yorkshire) Limited | York | 2013 |
| Alcuma Limited | Glasgow | 2020 |
| ALD (Health & Safety) Limited | Glasgow | 2017 |
| ALD 8 Limited | Poole | 2010 |
| ALD Access Solutions Ltd | Maidstone | 2018 |
| ALD Brown Limited | Herne Bay | 2018 |
| ALD Builders Limited | Birmingham | 2021 |
| ALD Construction and Landscaping Ltd | London | 2016 |
| ALD Construction Limited | Leicester | 2023 |
| ALD Contracts Ltd | Chigwell | 2014 |
| ALD Creators for Building and Decoration Ltd | Harrow | 2023 |
| ALD Electrical Ltd | Crawley | 2025 |
| ALD Electrical Solutions Limited | Bushey | 2025 |
| ALD Electrics Ltd | Stourport-On-Severn | 2008 |
| ALD Facades Holdings Limited | Nottingham | 2025 |
| ALD Facades Limited | Calverton | 2017 |
| ALD Fire Protection Ltd | Dagenham | 2023 |
| ALD Flat Roofing Limited | Nottingham | 2024 |
| ALD Floor Screed Limited | Nottingham | 2023 |
| ALD Groupco Limited | Nottingham | 2025 |
| ALD Interiors Limited | Liverpool | 2018 |
| ALD3 Limited | Poole | 2007 |
| Alda Glazing Solutions Ltd | Bromley | 2023 |
| Alda Property Limited | Hertford | 2012 |
| Aldababat Services Ltd | Luton | 2019 |
| Aldam Plumbing and Electrical Services Ltd | Bromley | 2018 |
| Aldama Ltd | Romford | 2017 |
| Aldan Building Solutions Limited | Sheffield | 2013 |
| Aldan Electrical Engineering Ltd | Liverpool | 2023 |
| Aldan Ltd | Wirral | 2022 |
| Aldanigema Limited | London | 2025 |
| Aldar Construction Ltd | Bathgate | 2022 |
| Aldau Hotel Investments Limited | London | 2018 |
| Aldborough Court (SK) Ltd | London | 2026 |
| Aldborough Refurbishments Limited | Benfleet | 2013 |
| Aldbury Homes (Eagle Farm) Ltd | Milton Keynes | 2018 |
| Aldbury Homes (Lockington) Ltd | Milton Keynes | 2019 |
| Aldbury Homes (Maulden) Ltd | Milton Keynes | 2021 |
| Aldbury Homes (Northill) Ltd | Milton Keynes | 2019 |
| Aldbury Homes (Slapton) Ltd | Milton Keynes | 2018 |
| Aldbury Homes (YG) Ltd | Milton Keynes | 2022 |
| Aldbury Homes Ltd | Milton Keynes | 2014 |
| Aldc Limited | Pinner | 2019 |
| Aldco Ltd | Basildon | 2023 |
| Aldcroft Group Ltd | Norwich | 2024 |
| Alde Developments Limited | Stratford, | 1970 |