| Aiman Building Limited | Real estate | 2024 |
| Aimi Consulting Services Limited | Administrative & support | 2025 |
| Aims FM Limited | Construction | 2005 |
| Aims Software Solutions Ltd | Professional & scientific | 2005 |
| Air Fuel Systems Limited | Extraterritorial | 2013 |
| Air Heating (Southern) Limited | Professional & scientific | 2016 |
| Air Plus (UK) Limited | Construction | 2013 |
| Air Source Heat Limited | Extraterritorial | 2012 |
| Air VIP Concierge Tours Limited | Transport & logistics | 2025 |
| Airborne SIX Ltd | Professional & scientific | 2025 |
| Aircross Express Investments Ltd | Mining & quarrying | 2025 |
| Airflow Building Services Ltd | Construction | 2025 |
| Airvip London Ltd | Transport & logistics | 2025 |
| Aiza Property Investments Ltd | Real estate | 2026 |
| AJ & R Ltd | Information & communication | 2020 |
| AJ Consultants and Bookkeepers Limited | Professional & scientific | 2020 |
| AJ Fisheries Limited | Wholesale & retail | 2024 |
| AJ Network Consultancy Limited | Information & communication | 2018 |
| AJ Sidcup Holdings Ltd | Real estate | 2026 |
| AJ Sport U.K Ltd | Hospitality | 2026 |
| AJ Team Ltd | Construction | 2023 |
| AJ White PPM Professional Ltd | Professional & scientific | 2022 |
| AJ Windows Essex Limited | Construction | 2025 |
| Ajan 2026 Ltd | Hospitality | 2026 |
| AJC Group Services Ltd | Real estate | 2024 |
| AJH Maintenance Solutions Limited | Administrative & support | 2018 |
| AJJ Electrical Engineering Limited | Construction | 2022 |
| Ajkd Products Ltd | Wholesale & retail | 2025 |
| AJP Associates Ltd | Hospitality | 2020 |
| AJS Contractors Limited | Construction | 2020 |
| AJS Performance Limited | Professional & scientific | 2018 |
| AJS Welding Limited | Construction | 2002 |
| AKA 35 Limited | Information & communication | 2026 |
| AKA Technologies Limited | Wholesale & retail | 2018 |
| Akensa Limited | Wholesale & retail | 2026 |
| Akeso Psychosocial Services Ltd | Other services | 2012 |
| Akhenaten Limited | Hospitality | 2019 |
| Akins Auto Ltd | Wholesale & retail | 2026 |
| AKR Building Limited | Construction | 2021 |
| Aksairaa Ltd | Wholesale & retail | 2025 |
| Aksha Ltd | Wholesale & retail | 2019 |
| AL Angels Limited | Other services | 2024 |
| AL Carpet Ltd | Construction | 2019 |
| AL Clinic (Essex) Limited | Health & social care | 2024 |
| AL Mamun Properties Ltd | Real estate | 2015 |
| AL Web Services Limited | Information & communication | 2018 |
| Alan FEW & Co Ltd | Construction | 2005 |
| Alan S Investments | Professional & scientific | 2025 |
| Alankrita Homes Ltd | Real estate | 2019 |
| Alankrita Ltd. | Administrative & support | 2009 |
| Alaseyori Global Limited | Arts & recreation | 2024 |
| ALB Greek Bites Ltd | Hospitality | 2024 |
| Alban Property Improvers Ltd | Other services | 2013 |
| Albby Ltd | Wholesale & retail | 2024 |
| Albert Perfusion Ltd | Health & social care | 2022 |
| Albright Design Limited | Professional & scientific | 2024 |
| Albus John Willow Company Limited | Construction | 2026 |
| Alcon Health Ltd | Public administration | 2019 |
| Aldco Ltd | Construction | 2023 |
| ALE BG Ltd | Transport & logistics | 2025 |
| Alentra Limited | Wholesale & retail | 2026 |
| Alert Pest Control Environmental Limited | Administrative & support | 2020 |
| Alert Pest Control LLP | | 2007 |
| Alestrate Trans Ltd | Transport & logistics | 2024 |
| Alex & GA Limited | Transport & logistics | 2012 |
| Alex & VIO Trans Ltd | Administrative & support | 2019 |
| Alex Motor Accident Repairs and Claims Management Ltd | Wholesale & retail | 2016 |
| Alex N Ltd | Transport & logistics | 2018 |
| Alex Tracking Ltd | Construction | 2016 |
| Alexidama Ltd | Construction | 2018 |
| Alexisfilip Ltd | Construction | 2021 |
| Alexjay & Company Ltd | Information & communication | 2019 |
| Alexmatt Limited | Transport & logistics | 2023 |
| Alexmb Limited | Construction | 2026 |
| Alexro Limited | Construction | 2014 |
| Alf's Electrical Ltd | Construction | 2021 |
| Alfalah Travel Limited | Administrative & support | 2025 |
| Algarve Express Limited | Administrative & support | 2016 |
| Alicense Ltd | Professional & scientific | 2025 |
| Alico Distribution Ltd | Wholesale & retail | 2020 |
| Alin&Antonia Ltd | Transport & logistics | 2020 |
| Aliso Veijo Limited | Information & communication | 2012 |
| ALL About Fencing Ltd | Manufacturing | 2013 |
| ALL Best Cargoes Ltd | Transport & logistics | 2026 |
| ALL Build 1 Ltd | Construction | 2015 |
| ALL Good Logisitics Ltd | Administrative & support | 2023 |
| ALL in MEZ Ltd | Hospitality | 2026 |
| ALL in One Contracts Ltd. | Other services | 2017 |
| ALL Muscle Gym Limited | Arts & recreation | 2022 |
| ALL Seasons Food & Drinks Ltd | Wholesale & retail | 2019 |
| ALL Seasons Young Living Ltd | Hospitality | 2020 |
| All-Form Group Limited | Construction | 2018 |
| All-Highs Limited | Construction | 2015 |
| Allcoats Limited | Other services | 2018 |
| Allen Construction Ltd | Construction | 2021 |
| Allen Street Ltd | Real estate | 2025 |
| Alliance Street Accountancy Ltd | Professional & scientific | 2024 |
| Allin 1WORK Ltd | Construction | 2024 |
| Allinson Industry Ltd | Construction | 2020 |
| Allison Commercial Properties Limited | Real estate | 2018 |