| Aegis Financial Services Limited | Financial services | 2024 |
| Aegis PAY Ltd | Professional & scientific | 2025 |
| Aegis Privacy Consulting Limited | Professional & scientific | 2016 |
| Aegis Training Consultancy Limited | Extraterritorial | 2016 |
| Aegis Vaults Ltd | Wholesale & retail | 2022 |
| Aegm Ltd | Professional & scientific | 2024 |
| Aegyptus Limited | Hospitality | 2017 |
| AEL Tooling Limited | Wholesale & retail | 2005 |
| Ael-Y-Bryn Limited | Health & social care | 2015 |
| Aelel Larbt Ltd | Wholesale & retail | 2024 |
| AEM Consult Ltd | Professional & scientific | 2022 |
| AEM Properties (Cardiff) Limited | Real estate | 2020 |
| Aenulltech Ltd | Information & communication | 2025 |
| AEO Site Lift Ltd | Information & communication | 2025 |
| Aeo-Media Limited | Professional & scientific | 2024 |
| Aeolos Energy Investments Ltd | Financial services | 2021 |
| Aeon Trading Limited | Information & communication | 2013 |
| Aeonspark Ehub Ltd | Wholesale & retail | 2025 |
| Aeoraspan Ltd | Wholesale & retail | 2025 |
| AEQ Consultants Limited | Construction | 2016 |
| Aequalis Accountancy Limited | Professional & scientific | 2021 |
| Aequalis Limited | Professional & scientific | 2018 |
| AER Technologies Ltd | Information & communication | 2021 |
| Aerczech Limited | Transport & logistics | 2019 |
| Aerial Craft Ltd | Administrative & support | 2013 |
| Aerialmasters Limited | Information & communication | 2019 |
| Aeriousgroup Ltd | Information & communication | 2024 |
| Aerivon Ltd | Wholesale & retail | 2025 |
| Aero Asian Textiles Ltd | Wholesale & retail | 2015 |
| Aero Electrical (South Yorkshire) Ltd | Construction | 2019 |
| Aero Engine Services Ltd | Wholesale & retail | 2020 |
| Aero Launch PVT Ltd | Information & communication | 2024 |
| Aero Properties Group Limited | Real estate | 2020 |
| Aero QAZ Limited | Professional & scientific | 2015 |
| Aero Repairs and Spares Solutions Ltd | Professional & scientific | 2017 |
| Aero Structure UK Limited | Construction | 2012 |
| Aero Tech Services Limited | Construction | 2015 |
| Aerodreams Ltd | Administrative & support | 2025 |
| Aeron (Barry) Limited | Real estate | 2022 |
| Aeron Holdings Limited | Real estate | 2019 |
| Aeron NH Limited | Real estate | 2021 |
| Aeron Properties Limited | Real estate | 2008 |
| Aeron Ventures Limited | Financial services | 2024 |
| Aeronomads Ltd | Wholesale & retail | 2025 |
| Aerospark Limited | Manufacturing | 2025 |
| Aerotech Engineering Limited | Professional & scientific | 2024 |
| AES Group Machinery UK Ltd | Wholesale & retail | 2023 |
| Aesrhea Laboratories Limited | Extraterritorial | 2018 |
| Aesthetic Gardens and Drives Ltd | Administrative & support | 2006 |
| Aesthetic Vision Ltd | Health & social care | 2024 |
| Aesthetically Appealing Ltd | Other services | 2025 |
| Aesthetics by AMY Rose Limited | Health & social care | 2020 |
| Aesthetics by DR TOM Ltd | Health & social care | 2024 |
| Aesthetics Supplies Ltd | Wholesale & retail | 2019 |
| Aeternum Discoveries Limited | Professional & scientific | 2026 |
| Aetherflow Ltd | Education | 2025 |
| Aetheris Technology Ltd. | Financial services | 2025 |
| Aethernex Limited | Information & communication | 2025 |
| Aethr Holdings Ltd | Wholesale & retail | 2023 |
| Aetios AI Ltd | Information & communication | 2025 |
| AF Builders of West Midlands Ltd | Construction | 2024 |
| AF Mechanical Services Ltd | Construction | 2022 |
| AF Rigging Ltd | Professional & scientific | 2026 |
| Af-Personaltraining Ltd | Other services | 2025 |
| AFA Building & Maintenance Ltd | Construction | 2026 |
| AFA Building Services London Limited | Construction | 2001 |
| AFA Digital Ltd | Information & communication | 2019 |
| Afallen LLP | | 2018 |
| Afango Limited | Administrative & support | 2026 |
| Afanti Media Limited | Information & communication | 1995 |
| AFB Cardiff Ltd | Hospitality | 2025 |
| Afdhaal Ltd | Transport & logistics | 2019 |
| Afds International Limited | Extraterritorial | 2019 |
| Afeez Broadway Ltd | Professional & scientific | 2019 |
| Afendi Ingredients Limited | Wholesale & retail | 2025 |
| Afendi Ltd | Wholesale & retail | 2015 |
| Afendi Partnership Ltd | Financial services | 2025 |
| Afey Products Limited | Wholesale & retail | 2021 |
| Afferent Medical Solutions Ltd | Professional & scientific | 2019 |
| Affiliatz Ltd | Information & communication | 2024 |
| Affilx Ltd | Wholesale & retail | 2014 |
| Affini-Tree Limited | Agriculture & fishing | 2018 |
| Affinity Care Recruitment Ltd | Health & social care | 2009 |
| Affinity Maintenance Limited | Water & waste | 2018 |
| Affinity Payroll Solutions Limited | Administrative & support | 2018 |
| Affirmxh Ltd | Professional & scientific | 2020 |
| Affluence Global Nutrition and Wellness UK Ltd | Manufacturing | 2026 |
| Affluent Goods Limited | Manufacturing | 2025 |
| Affluent Properties Ltd | Real estate | 2021 |
| Affluent Universe Limited | Financial services | 2013 |
| Affordable Bullion Ltd | Wholesale & retail | 2025 |
| Affordable Cars Cardiff Ltd | Wholesale & retail | 2023 |
| Affordable Homes (Wales) Limited | Administrative & support | 2008 |
| Affordable LOG Burners Ltd | Construction | 2022 |
| Affordable Renovations and Maintenance Limited | Construction | 2019 |
| Affordable Talk CIC | Health & social care | 2020 |
| Affordable Warmth Ltd | Manufacturing | 2018 |
| Affordwise Ltd | Information & communication | 2023 |
| AFG Auto MOT Centre Limited | Manufacturing | 2013 |
| AFG Handcarwash Ltd | Administrative & support | 2025 |