| Alternative Arrangements Ltd | Bury | 2013 |
| Alternative Cake Co Ltd | Stourbridge | 2025 |
| Alternative Centre (Dumfries) Limited | Heathhall, Dumfries | 2003 |
| Alternative Energy Developments PLC | Leicester | 2010 |
| Alternative Fashion Ltd | Glasgow | 2022 |
| Alternative Footwear Limited | Ramsbottom | 2026 |
| Alternative Fuel Co Ltd | Croydon | 2007 |
| Alternative Fuel Diagnostics Ltd | Epsom | 2019 |
| Alternative Furniture Company Limited | Newark | 2002 |
| Alternative Gardens Limited | Ruardean | 2010 |
| Alternative Heating Solutions Limited | Colchester | 2020 |
| Alternative Intelligent Solutions Ltd | Birmingham | 2017 |
| Alternative Interiors (Ribble Valley) Ltd | Longridge | 2024 |
| Alternative Investment Options Ltd | Oakham | 2024 |
| Alternative Investments Management Company Ltd | London | 2018 |
| Alternative Kidz Club Ltd | London | 2020 |
| Alternative Lifestyle Limited | Leeds | 2001 |
| Alternative Lighting Solutions Ltd | Preston | 2012 |
| Alternative Market and Creative Hub Limited | Battle | 2025 |
| Alternative Meats Limited | Whitchurch | 2001 |
| Alternative Outdoor Ltd | Hampshire | 2006 |
| Alternative Outlet Limited | Letchworth Garden City | 2024 |
| Alternative Packaging Limited | Beaconsfield | 1984 |
| Alternative Packaging Solutions Limited | Alton | 1996 |
| Alternative Plastics Limited | Bermuda Industrial Estate | 1987 |
| Alternative Records Ltd | Birmingham | 2010 |
| Alternative Scents Limited | Edinburgh | 2023 |
| Alternative Sentiments Ltd | St. Albans | 2021 |
| Alternative Shop Ltd | London | 2025 |
| Alternative Supermarket Venture Ltd | Harrow | 2024 |
| Alternative Teas Ltd | London | 2025 |
| Alternative Tiles Limited | Derby | 2007 |
| Alternative Timber Limited | Edinburgh | 1999 |
| Alternative Tying Systems Ltd | Redditch | 2013 |
| Alternative Vehicle Solutions Ltd | Newcastle Upon Tyne | 2024 |
| Alternative Windscreens Limited | Fareham | 2012 |
| Alternatives Trading Limited | Hemel Hempstead | 2013 |
| Alternativessels Ltd | London | 2022 |
| Alternergy Limited | London | 2006 |
| Alternergy Renewables Ltd | London | 2026 |
| Alternity Apparel Ltd | New Milton | 2014 |
| Alternova UK Ltd | London | 2023 |
| Altero Eyewear Ltd | Bristol | 2026 |
| Alterrain Clothing Ltd | Leeds | 2025 |
| Alterre Ltd | London | 2026 |
| Alterstart UK Ltd | Newton Abbot | 2019 |
| Alterv Health Ltd | Lewes | 2025 |
| Alterytis HR Ltd | Manchester | 2020 |
| Altessa Ltd | London | 2025 |
| Altesse Limited | Hertfordshire | 2005 |
| Alteus Limited | Wadhurst | 2017 |
| Alteus Wines Limited | Wadhurst | 2018 |
| Altex (UK) Limited | Leeds | 1982 |
| Altex (Wales) Limited | Kidwelly | 2002 |
| ALTF4 Ltd | London | 2026 |
| Altfield Limited | Seend | 1992 |
| Altfood Ltd | Slough | 2025 |
| Altgrl Ltd | Bromley | 2025 |
| Alth Trading Limited | Newark | 2025 |
| Althahm Almontaliq Lelamaal Ltd | Manchester | 2025 |
| Althaia Ltd | Potters Bar | 2020 |
| Althakeel General Trading Ltd | London | 2026 |
| Altham Car Recyclers Limited | Preston | 2003 |
| Altham Limited | Hitchin | 2003 |
| Althaus Specor Team Ltd | London | 2025 |
| Althea Beauty Ltd | Leeds | 2017 |
| Althea J UK Limited | London | 2024 |
| Althea London Co. Ltd | London | 2026 |
| Althea Therapeutics Ltd | London | 2025 |
| Althea Tomlin Skincare Limited | Nottingham | 2010 |
| Althemax International Limited | Bury St. Edmunds | 2025 |
| Altheray Ltd | London | 2026 |
| Altheria Limited | London | 2025 |
| Altheris UK Ltd | Dulwich | 2025 |
| Altherm System Build Limited | Hertford | 2025 |
| Althero Ltd | London | 2025 |
| Althie Lifestyle Limited | Croydon | 2021 |
| Althon Limited | | 1981 |
| Althorp Road Specsavers Hearcare Limited | Fareham | 2019 |
| Althorp Road Specsavers Limited | Fareham | 2016 |
| Althulooj Almutanathirah Training for Wholesale and Retail Trade Company Ltd | Harrogate | 2025 |
| Alti Bolaq Carpets Limited | Norwich | 2004 |
| Alti Group Limited | London | 2026 |
| Alti's Food Centre Northampton Limited | London | 2025 |
| Altia Estates (Nott) Limited | Selby | 2022 |
| Altibrew Ltd | Carnforth | 2024 |
| Altico (Holdings) Ltd | Doncaster | 2021 |
| Altico Garden Products Ltd | Doncaster | 2013 |
| Altid Limited | Colchester | 2020 |
| Altida Hire and Transport Ltd | Enfield | 2025 |
| Altie Ltd | Altrincham | 2024 |
| Altiege Ltd | London | 2026 |
| Altiel Limited | Milton Keynes | 2011 |
| Altigen Consultancy Ltd | London | 2022 |
| Altigma Ltd | Reading | 2026 |
| Altijara Ltd | Luton | 2025 |
| Altijarat INT Ltd | London | 2023 |
| Altikx Capital UK Ltd | London | 2025 |
| Altili Limited | London | 2025 |
| Altima Limited | Pinner | 2026 |