| Alan Jacobs Mediation Ltd | Professional & scientific | 2019 |
| Alan Schaller Productions Limited | Administrative & support | 2023 |
| Aland Food Ltd | Wholesale & retail | 2026 |
| Alandrea Investments Limited | Real estate | 2006 |
| Alaoma International Foods, Drinks & Spices Limited | Wholesale & retail | 2016 |
| Alaoma Nigerian Cuisine Ltd | Hospitality | 2025 |
| Alarm Doctor Privilege Club Limited | Extraterritorial | 2007 |
| Alas Properties Limited | Real estate | 2018 |
| Alas Services Limited | Professional & scientific | 2003 |
| Alasdair Griffiths Ltd | Professional & scientific | 2016 |
| Alaska Gida Sogutma Ltd | Wholesale & retail | 2023 |
| Alawi Desserts Ltd | Wholesale & retail | 2017 |
| Alayah Courier Ltd | Transport & logistics | 2021 |
| Alaynas Store Ltd | Wholesale & retail | 2017 |
| Alb-Auto Company Ltd | Wholesale & retail | 2019 |
| Albaline Properties Limited | Hospitality | 2025 |
| Albarari Foods Ltd | Wholesale & retail | 2025 |
| Albatati Extra Limited | Wholesale & retail | 2023 |
| Albatati Limited | Wholesale & retail | 2025 |
| Albatati Property Ventures Limited | Real estate | 2024 |
| Albert IT Solutions Ltd | Information & communication | 2023 |
| Albert Lofts Management Company Limited | Households | 2019 |
| Albert Road Sheffield Management Company Limited | Households | 2006 |
| Albies Coffee Limited | Wholesale & retail | 2018 |
| Albion Detection Ltd | Administrative & support | 2025 |
| Albion Detection Systems Limited | Administrative & support | 1997 |
| Albion Language Trips Limited | Education | 2024 |
| Albion Sheff Limited | Hospitality | 2018 |
| Albion Surgicals Limited | Wholesale & retail | 1995 |
| Albion Timber Ltd. | Wholesale & retail | 2021 |
| Albo Integrated Services Limited | Transport & logistics | 2026 |
| Alborada Media Ltd | Information & communication | 2010 |
| Albpubs Ltd | Administrative & support | 2025 |
| Albrecht & Dowbusz Properties Ltd | Real estate | 2018 |
| Albrecht International Ltd | Education | 2018 |
| Albus Digital Ltd | Information & communication | 2023 |
| ALC Business College UK Ltd | Education | 2023 |
| ALC Health Ltd | Health & social care | 2025 |
| ALC Study Ltd | Professional & scientific | 2019 |
| Alchemist Aesthetics Ltd | Other services | 2017 |
| Alchemy Film and TV Ltd | Information & communication | 2022 |
| Alchemy Grove Holistic Therapy Ltd | Other services | 2025 |
| Alcium Software Limited | Information & communication | 2001 |
| Alcm Design Limited | Information & communication | 2021 |
| Aldan Building Solutions Limited | Construction | 2013 |
| Aldanex Limited | Professional & scientific | 2022 |
| Aldene Developments Limited | Construction | 2015 |
| Alder Inns Limited | Hospitality | 2025 |
| Aldercote Limited | Manufacturing | 1999 |
| Alderstack Limited | Information & communication | 2026 |
| Aldory Medical Ltd | Health & social care | 2014 |
| Aldwarke Developments Ltd | Construction | 2021 |
| Aldwych Street Light Limited | Hospitality | 2016 |
| Aleb Limited | Professional & scientific | 2014 |
| Alebeacakes Ltd | Manufacturing | 2025 |
| Alebro Limited | Hospitality | 2016 |
| Alechemist Limited | Manufacturing | 2020 |
| Aleena Catering Ltd | Hospitality | 2026 |
| Alef Catering Limited | Hospitality | 2019 |
| Alehouse Academy Limited | Hospitality | 2026 |
| Alem Leisure Limited | Hospitality | 2015 |
| Alen's Classic Barbers Ltd | Other services | 2026 |
| Alenezi Group Ltd | Wholesale & retail | 2024 |
| Aleo Investments Limited | Real estate | 2019 |
| Aleo Solutions Limited | Administrative & support | 2019 |
| Alepothecary Limited | Hospitality | 2021 |
| Alert-Hub.Org CIC | Information & communication | 2021 |
| Alethea & Co (London) Limited | Professional & scientific | 2015 |
| Aleti Solutions Limited | Information & communication | 2026 |
| Alew Ltd | Real estate | 2019 |
| Alex Brown Consultancy Ltd | Professional & scientific | 2022 |
| Alex Brown Medical Ltd | Health & social care | 2021 |
| Alex Gerrard Ltd | Professional & scientific | 2013 |
| Alex Goddard Limited | Professional & scientific | 2021 |
| Alex Hunting Limited | Professional & scientific | 2015 |
| Alex Power UK Ltd | Wholesale & retail | 2018 |
| Alex Pubs Ltd | Hospitality | 2025 |
| Alex Rofin Ltd | Transport & logistics | 2026 |
| Alex Roley Individual Estate Agent Ltd | Real estate | 2026 |
| Alexander (Commercial Property) Limited | Real estate | 2008 |
| Alexander Court Nursing Home Limited | Health & social care | 2023 |
| Alexander Engraving Limited | Wholesale & retail | 2008 |
| Alexander Estates & Letting Agents Ltd | Real estate | 2011 |
| Alexander Harris (Altrincham) Limited | Extraterritorial | 1995 |
| Alexander Wells Limited | Arts & recreation | 2020 |
| Alexanders Property Ltd | Real estate | 2023 |
| Alexandra Pavone Dance Ltd | Arts & recreation | 2024 |
| Alexandra Socials Ltd | Arts & recreation | 2024 |
| Alexio Plumbing Ltd | Construction | 2025 |
| Alexis James Property Ltd | Real estate | 2018 |
| ALF Hales and Sons Ltd | Wholesale & retail | 2023 |
| Alf's Fresh Pasta Ltd | Hospitality | 2024 |
| Alfa GAS Services Ltd | Construction | 2018 |
| Alfahad Services Limited | Transport & logistics | 2025 |
| Alfie Marlow Ltd | Professional & scientific | 2006 |
| Alfra (UK) Ltd. | Wholesale & retail | 2021 |
| Alfred Grindrod & Co. Limited | | 1900 |
| Alfred Support Services Ltd | Administrative & support | 2025 |
| Algar Air Compressed Air Engineers Ltd | Manufacturing | 2011 |
| Algor Limited | Administrative & support | 2012 |