| App Agentic Ltd | Information & communication | 2025 |
| App Proxy Limited | Information & communication | 2021 |
| Apparel Studio Ltd | Manufacturing | 2013 |
| Appends Consulting Ltd | Professional & scientific | 2015 |
| Appiah & Associates Limited | Professional & scientific | 2007 |
| Apple Care Group Ltd | Real estate | 2025 |
| Apple Care One Limited | Health & social care | 2023 |
| Apple Catering Limited | Hospitality | 2005 |
| Appleby Lodge Management Company Limited | Households | 1970 |
| Appleford Homes Limited | Health & social care | 2019 |
| Applegarth Investments Limited | Real estate | 2016 |
| Applegreen Limited | Wholesale & retail | 1990 |
| Applegriff Limited | Administrative & support | 2008 |
| Appletree (NW) Ltd | Professional & scientific | 2016 |
| Applied Canine Science Ltd | Education | 2026 |
| Applied Chemicals Application Technology Limited | Wholesale & retail | 2009 |
| Applied Industrial Systems Limited | Information & communication | 1990 |
| Applied Industries Limited | Manufacturing | 1999 |
| Applied Investments Ltd. | Real estate | 1999 |
| Applied Systems Design Studio Ltd | Professional & scientific | 2024 |
| Appreciating Property Group Ltd. | Real estate | 2021 |
| Approved Hydraulics Limited | Wholesale & retail | 1990 |
| Appt Investments Ltd | Real estate | 2003 |
| Apritem Limited | Information & communication | 2016 |
| APS Catering and Electrical Services Ltd | Manufacturing | 2010 |
| APS Group Global Limited | Professional & scientific | 2008 |
| APS Group Holdco Limited | Financial services | 2021 |
| APS Group Limited | Financial services | 2019 |
| APS Group Secure Solutions Limited | Manufacturing | 2009 |
| Apsales Limited | Wholesale & retail | 2023 |
| Apsas (M&E) Ltd | Other services | 2024 |
| APT Building Compliance Ltd | Professional & scientific | 2025 |
| APT Cooling Solutions Ltd | Construction | 2015 |
| APT Pressure Washing Ltd | Administrative & support | 2025 |
| Aptimarketing Ltd | Professional & scientific | 2025 |
| APW Whelton Ltd | Financial services | 2014 |
| Aqal Property Ltd | Real estate | 2024 |
| Aqera Ltd | Information & communication | 2018 |
| Aqsascart Limited | Wholesale & retail | 2025 |
| Aqua Cube IT Limited | Information & communication | 2011 |
| Aqua Recoup Ltd | Professional & scientific | 2026 |
| Aquablu Limited | Construction | 2016 |
| Aquarius Cleaning Services (N.W.) Ltd | Administrative & support | 2000 |
| Aquarius Financial (Holdings) Limited | Financial services | 2023 |
| Aquaside Ltd | Administrative & support | 2005 |
| Aquatec Developments Limited | Financial services | 2022 |
| Aquatec NW Limited | Construction | 2016 |
| Aquatopia Ltd | Wholesale & retail | 2025 |
| Aquila Norway Ltd | Administrative & support | 2010 |
| Aquila Planning Services Ltd | Construction | 2022 |
| Aquilo Developments Ltd | Construction | 2018 |
| AR Connect Education Ltd | Education | 2023 |
| AR Hospitality Ventures Ltd | Hospitality | 2026 |
| AR Industries Steelstrip Limited | Manufacturing | 2002 |
| AR INT Ltd | Wholesale & retail | 2024 |
| AR Tapas Limited | Hospitality | 2019 |
| ARA Holdings (NW) Limited | Financial services | 2024 |
| Arabians Unlimited Limited | Agriculture & fishing | 2018 |
| Aragorn Solar Farm Limited | Energy | 2022 |
| Arain Corporations Ltd | Wholesale & retail | 2025 |
| Aranka Services Limited | Administrative & support | 2023 |
| Aranyaka Ltd | Professional & scientific | 2024 |
| ARB Sons Ltd | Hospitality | 2023 |
| Arber Industrial Engineering Ltd | Professional & scientific | 2023 |
| Arbitrage Holding Limited | Administrative & support | 2017 |
| Arbitrage Mobile Limited | Administrative & support | 2017 |
| Arbitrage Recycling Solution Limited | Administrative & support | 2018 |
| Arbour Artists Limited | Arts & recreation | 2019 |
| Arbour Holdings Limited | Manufacturing | 2009 |
| ARC Civil Engineering Services Limited | Construction | 2005 |
| ARC Mindset CIC | Education | 2025 |
| ARC Performance Limited | Other services | 2025 |
| ARC Roofing Northwest Limited | Construction | 2010 |
| ARC Supplies Limited | Wholesale & retail | 2019 |
| Arcadia Educational Services Ltd | Education | 2019 |
| Arcadia Roller Derby Limited | Arts & recreation | 2022 |
| Arcadian Digital Ltd | Administrative & support | 2018 |
| Arcaine Limited | Arts & recreation | 2022 |
| Arcane Global Limited | Administrative & support | 2021 |
| Arcaras Limited | Manufacturing | 2024 |
| Arce Management Ltd | Real estate | 2026 |
| Arcfor Ltd | Real estate | 2023 |
| Archaeopteryx Ltd | Information & communication | 2014 |
| Archer Street Garage Ltd | Wholesale & retail | 2025 |
| Arches Developments Ltd | Construction | 2021 |
| Archinovo Construction Ltd | Construction | 2024 |
| Architectural Building Services (NW) Limited | Construction | 2010 |
| Architectural Hardware Ltd | Wholesale & retail | 2021 |
| Architectural Solutions Limited | Professional & scientific | 2009 |
| Archivd Carbon Ltd | Manufacturing | 2025 |
| Arcline Properties Limited | Real estate | 2017 |
| Arcline Technologies Ltd | Information & communication | 2026 |
| Arco Aviation Ltd | Wholesale & retail | 2021 |
| Arcosur Limited | Real estate | 2022 |
| Arctic Seal (MCR) Limited | Construction | 2017 |
| Arcturus Data Analysis LLP | | 2022 |
| Arcturus Energy Limited | Manufacturing | 2016 |
| Arcturus Epcom Limited | Construction | 2016 |
| Arcturus Limited | Administrative & support | 2016 |
| ARD Foods Ltd | Hospitality | 2025 |