| Alps SRL Ltd | Kington | 2022 |
| Alpsart Ltd | Bury St. Edmunds | 2025 |
| Alpscool Industries UK Limited | Blackpool | 2023 |
| Alpunch Tooling Limited | Swindon | 1988 |
| Alqemi Ltd | Evesham | 2008 |
| ALR Controls Ltd | Clydebank | 2022 |
| ALR Embroidery Limited | Darlington | 2024 |
| ALR Network Solutions Ltd | Cwmbran | 2026 |
| ALR Spirit Ltd | Thatcham | 2025 |
| ALR Trading Limited | Lisburn | 2018 |
| Alrad Instruments Limited | Camberley | 1989 |
| Alranga Ltd | London | 2026 |
| Alrayyanldn Ltd | London | 2023 |
| Alrep London Ltd | Birmingham | 2023 |
| Alreyada Solutions Limited | London | 2025 |
| Alright Engineering Limited | Hednesford | 2020 |
| Alright Fabrications Limited | Hednesford | 2009 |
| Alrima Commercial Limited | London | 2021 |
| Alrob Group Ltd | Birmingham | 2024 |
| Alrod Limited | Merthyr Tydfil | 1986 |
| Alrog Engineering Limited | Ilford | 1977 |
| Alrollers Limited | Wigan | 2007 |
| Alron Electrical Services Limited | Basingstoke | 2009 |
| Alrose Products Limited | Peterborough | 1985 |
| Alroy Microwave & Electronics Limited | Stevenage | 1965 |
| Alroy Sheet Metals Limited | Stevenage | 1961 |
| ALS (Hull) Ltd | Hull | 2024 |
| ALS Catering & Transport Company Limited | Watford | 2017 |
| ALS Dental Laboratories Group Limited | London | 2022 |
| ALS Electrical Ltd | London | 2021 |
| ALS Engineering Ltd | Whyteleafe | 2018 |
| ALS Fabrications Limited | Cheltenham | 2023 |
| ALS Fabs Limited | Telford | 2009 |
| ALS Furniture Limited | Loughton | 2023 |
| ALS Guitar Services Limited | Ventnor | 2025 |
| ALS Industrial Services Ltd | Warwick | 2016 |
| ALS Labs Limited | Leigh On Sea | 2011 |
| ALS Limited | Northants | 1993 |
| ALS Lock Tools Ltd | Slough | 2022 |
| ALS Mechatronic Limited | Cheltenham | 2002 |
| ALS Pallets Limited | Ellesmere Port | 2025 |
| ALS Property Maintenance Limited | Swansea | 2019 |
| ALS South Limited | London | 2025 |
| ALS Survival Ltd | Glasgow | 2020 |
| Als(Shanghai)Technology Limited | West Midlands, England | 2024 |
| Alsadiq&Sons Logistics Service Limited | Birmingham | 2022 |
| Alsager Electrical Ltd | Congleton | 2011 |
| Alsager Precision Limited | Wistaston Road Crewe | 2003 |
| Alsager Printing Company Limited | Newcastle | 1979 |
| Alsamex Products Limited | Bedford | 1957 |
| Alscot Timber & Woodworking Supplies Limited | Bromsgrove | 2002 |
| Alse International Limited | Buckingham | 2010 |
| Alsecco (U.K.) Limited | Stone | 2024 |
| Alser (UK) Limited | Faringdon | 1988 |
| Alshamyat Pastries Ltd | Manchester | 2021 |
| Alsico Laucuba Ltd | Preston | 2007 |
| Alsil Limited | Milton Keynes | 2016 |
| Alsimpson Civil and Utility Services Ltd | Motherwell | 2015 |
| Alsindbad Ltd | Sheffield | 2020 |
| Alsis Engineering Ltd | London | 2016 |
| Alskling Label Ltd | London | 2025 |
| Alsleben London Ltd | London | 2024 |
| Also Aussi Ltd | London | 1996 |
| Also Known AS Limited | Sheffield | 2005 |
| Also UK and Emerging Markets Ltd. | Bristol | 2025 |
| Alson Engineering Limited | Walsall | 2003 |
| Alsoor Dena Petrochemical Ltd | Leeds | 2022 |
| Alsop & Walker Limited | Five Ashes | 2006 |
| Alsoprint Limited | West Wickham | 2017 |
| Alssen Ltd | London | 2024 |
| Alsta Ltd | Glasgow | 2017 |
| Alstans Roller Shutters Ltd | Bootle | 2018 |
| Alstom Automation International Ltd | Street Birmingham | 1923 |
| Alstom Engineering and Services Limited | Derbyshire | 1988 |
| Alstom Product and Services Limited | Derby | 2006 |
| Alstom T&D Protection & Control Ltd | | 1969 |
| Alstom Transport UK Limited | Derby | 2013 |
| Alston Asset Management Ltd | Colchester | 2018 |
| Alston Buildworks Limited | Hyde | 2025 |
| Alston Electrical Limited | Crowborough | 2015 |
| Alston Electrical Services Ltd | Sunderland | 2015 |
| Alston Pre-Applied Limited | Preston | 1980 |
| Alstons (Cabinets) Limited | Colchester | 1938 |
| Alstons (Upholstery) Limited | Colchester | 1951 |
| Alsultan Sweets Ltd | Aylesbury | 2023 |
| Alsure Limited | Birmingham | 1992 |
| ALT - Solar Limited | Worcester | 2019 |
| ALT Berg Limited | Richmond | 1990 |
| ALT Bike Co Limited | Eccles | 2013 |
| ALT Circle Health Limited | Stanmore | 2022 |
| ALT CNC Machine Tool Services Ltd. | Walsall | 2013 |
| ALT Engineering Company Limited | Oldham | 1998 |
| ALT MLK Limited | Woodford Green | 2024 |
| ALT Precision Ltd | Thetford | 2024 |
| ALT Renewables Ltd | Weston-Super-Mare | 2023 |
| ALT Rubber & Plastics Limited | Chesterfield | 2025 |
| ALT Silk Ltd | London | 2023 |
| ALT Works Ltd | London | 2015 |
| ALT ZME Ltd | Birmingham | 2023 |
| Alt*Ego Ltd | Esher | 2022 |