| Awfer Tech Ltd | Information & communication | 2024 |
| AWJ Carpentry Ltd | Manufacturing | 2020 |
| Awmcs Ltd | Real estate | 2015 |
| AWP Plant Training Ltd | Construction | 2016 |
| Awpc Holdings Limited | Professional & scientific | 2024 |
| Awrsculpa Ltd | Professional & scientific | 2025 |
| AWS Bristol Limited | Professional & scientific | 2006 |
| AWS Expedition Ltd | Transport & logistics | 2022 |
| AWT Design Consulting Ltd | Professional & scientific | 2020 |
| AWT Properties Ltd | Real estate | 2023 |
| AWW Employee Trust Limited | Financial services | 2023 |
| Axelblu Ltd | Wholesale & retail | 2019 |
| Axentara Limited | Wholesale & retail | 2026 |
| Axente Limited | Professional & scientific | 2013 |
| Axiom Control Advisory Ltd | Information & communication | 2026 |
| Axiom Core Ltd | Information & communication | 2026 |
| Axiom Cyber Intelligence Limited | Information & communication | 2012 |
| Axiom Strength Ltd | Manufacturing | 2026 |
| Axion Clean Co Limited | Administrative & support | 2026 |
| Axion Trader Ltd | Wholesale & retail | 2026 |
| Axioniz Ltd | Information & communication | 2024 |
| Axis Actuarial Consulting Ltd | Administrative & support | 2020 |
| Axis Freedom Limited | Arts & recreation | 2016 |
| Axis Trampoline Club Limited | Arts & recreation | 2014 |
| Axis Visuals Limited | Information & communication | 2026 |
| Axisline Wholesale Limited | Wholesale & retail | 2025 |
| AXJ Directive Ltd | Information & communication | 2024 |
| AXL Consulting Ltd | Professional & scientific | 2023 |
| AXL Medical Ltd | Health & social care | 2026 |
| Axleaf Limited | Professional & scientific | 2024 |
| AXM Studios Ltd | Information & communication | 2021 |
| Axmet Solutions Ltd | Information & communication | 2023 |
| Axminster Decorating Services Limited | Construction | 1998 |
| Axonara Ltd | Information & communication | 2026 |
| Axpaul Media Limited | Information & communication | 2016 |
| Axsor Eagle UK Ltd | Wholesale & retail | 2025 |
| Axtec Business Support Limited | Professional & scientific | 2016 |
| Ayamira Events Ltd | Administrative & support | 2026 |
| Ayaura Ltd | Wholesale & retail | 2024 |
| Ayden Food Ltd | Hospitality | 2023 |
| Ayeeyo and Awoowo Daryeel CIC | Health & social care | 2022 |
| Ayers Forestry Limited | Agriculture & fishing | 2012 |
| Ayeye Group Ltd | Other services | 2025 |
| Ayilaran Academy Ltd | Education | 2020 |
| Aylac Limited | Professional & scientific | 2024 |
| Aylesbury Glazing Ltd | Extraterritorial | 2021 |
| Aylesbury Window Repairs Ltd | Extraterritorial | 2020 |
| Aylieff Yasuda Limited | Other services | 2010 |
| Aylward Inns Limited | Other services | 2000 |
| Aymensa Ltd | Information & communication | 2026 |
| Ayohkay Ltd | Information & communication | 2017 |
| Ayone Limited | | 1982 |
| Ayra Mini Market Ltd | Wholesale & retail | 2025 |
| Ayrtek Cricket Limited | Wholesale & retail | 2016 |
| Aysop Ltd | Hospitality | 2018 |
| Ayt&S Project Consulting Ltd | Real estate | 2015 |
| Ayudas Virtual Assistants Ltd | Administrative & support | 2024 |
| Ayura Ltd | Wholesale & retail | 2025 |
| Ayush Plus UK Ltd | Wholesale & retail | 2025 |
| Ayushi Advertising Ltd | Information & communication | 2018 |
| Ayyman Group Limited | Administrative & support | 2015 |
| AZ and Co Collective Ltd | Construction | 2026 |
| AZ Curry House Ltd | Hospitality | 2021 |
| AZ Fruits and Vegetable Ltd | Wholesale & retail | 2024 |
| AZ Ventures Limited | Financial services | 2018 |
| Azad Trackers Ltd | Transport & logistics | 2025 |
| Azan Ltd | Transport & logistics | 2024 |
| Azbot Management Ltd | Wholesale & retail | 2016 |
| AZE Consultants-Azec Limited | Construction | 2014 |
| Azimuth Print Limited | Manufacturing | 1989 |
| Azinas (Bristol) Limited | Health & social care | 2016 |
| Aziz Family Investment Limited | Real estate | 2025 |
| Aziz Hoque Ltd | Arts & recreation | 2017 |
| Azlan Online Ltd | Wholesale & retail | 2025 |
| AZM Properties Group Limited | Extraterritorial | 2024 |
| AZM Property Group Limited | Extraterritorial | 2025 |
| AZM Property Investments Limited | Extraterritorial | 2024 |
| AZM Property Management Limited | Extraterritorial | 2021 |
| AZM Property Services Limited | Extraterritorial | 2024 |
| Azom Property Limited | Real estate | 2022 |
| Azora Project Management Ltd | Households | 2025 |
| Azora Solutions Limited | Professional & scientific | 2011 |
| Azra Technologies Ltd | Information & communication | 2022 |
| Azrek Limited | Real estate | 2021 |
| Aztec AVA Limited | Education | 1986 |
| Aztec Commercial Limited | Professional & scientific | 2006 |
| Aztec Paving Ltd | Construction | 2010 |
| Aztec Securities (Nationwide) Limited | Administrative & support | 2015 |
| Aztec Storage Containers Limited | Real estate | 2022 |
| Aztec Trucking Limited | Transport & logistics | 2023 |
| Aztec West Software Limited | Information & communication | 2015 |
| Azteca Roofing Limited | Construction | 2020 |
| Aztech Building Services Limited | Construction | 2002 |
| Aztech Floors and Walls Limited | Construction | 2004 |
| Azul Optics Limited | Manufacturing | 2016 |
| Azure IT Services Limited | Information & communication | 2011 |
| Azure Medica Limited | Health & social care | 2024 |
| Azusa 605 Ltd | Real estate | 2025 |
| Azzta Group Ltd. | Information & communication | 2000 |
| B & a Construction Bristol Limited | Construction | 2019 |