| Apex P S Ltd | Wholesale & retail | 2025 |
| Apex Property Maintenance Hull Ltd | Real estate | 2017 |
| Apex Renewable Contractors Limited | Construction | 2026 |
| Apex Rental Properties Ltd | Real estate | 2025 |
| APEXMART24 Ltd | Wholesale & retail | 2025 |
| Apiel Properties Ltd | Real estate | 2026 |
| APL Technical Services Limited | Construction | 2014 |
| Aplts Limited | Professional & scientific | 2018 |
| Apollo Autos (Grimsby) Ltd | Wholesale & retail | 2016 |
| Apollo Building and Maintenance Yorkshire Limited | Construction | 2026 |
| Apollo Group Management Holdings Limited | Financial services | 2023 |
| Applemont Anlaby Limited | Construction | 2019 |
| Applestone Properties Limited | Real estate | 2015 |
| Appletons Associates Limited | Financial services | 1953 |
| Appletree Homes Beverley Limited | Real estate | 2019 |
| Approved Autocentre Ltd | Wholesale & retail | 2020 |
| Aprolis UK Limited | Manufacturing | 1990 |
| Apron Strings Culinary Studio Ltd | Wholesale & retail | 2020 |
| APS (Hull) Ltd | Construction | 2014 |
| APS Delivery Limited | Transport & logistics | 2024 |
| Apuri Technology Limited | Information & communication | 2013 |
| APX Yorkshire Ltd | Real estate | 2026 |
| AQ Pouch House Hull Ltd | Wholesale & retail | 2023 |
| Aqua GAS (Hull) Limited | Construction | 2009 |
| Aqua Gear Technology Limited | Professional & scientific | 2018 |
| Aqua Shield (GB) Limited | Construction | 2007 |
| Aquafit Limited | Construction | 2006 |
| Aquatropic Limited | Wholesale & retail | 2013 |
| Aquerra Skincare Ltd | Administrative & support | 2025 |
| Aquila and Jide Investment Ltd | Wholesale & retail | 2021 |
| AR & RD Properties Limited | Real estate | 2023 |
| AR Business Support Ltd | Administrative & support | 2013 |
| AR Commissioning Services Limited | Manufacturing | 2016 |
| AR Deliveries Limited | Transport & logistics | 2025 |
| AR Estates Holdings Ltd | Construction | 2026 |
| AR Fuels Ltd | Wholesale & retail | 2019 |
| AR Market Ltd | Wholesale & retail | 2026 |
| AR Motors Group Ltd | Transport & logistics | 2023 |
| ARA0330 Ltd | Wholesale & retail | 2025 |
| Aram Zagros Limited | Transport & logistics | 2026 |
| Arasa Limited | Health & social care | 2024 |
| ARB (PM) Ltd | Professional & scientific | 2019 |
| Arbir Homes Ltd | Real estate | 2023 |
| Arborcare Services Ltd | Agriculture & fishing | 2022 |
| ARC Associates UK Ltd | Extraterritorial | 2007 |
| ARC Financial Consultants Limited | Professional & scientific | 2019 |
| ARC Lets (Hull) Limited | Real estate | 2022 |
| Arcadian Curios Ltd | Wholesale & retail | 2025 |
| Archers Green (Olga Road) Management Company Limited | Households | 2004 |
| Archie's Joinery Services Ltd | Construction | 2024 |
| Archie’S Detroit Pizza Limited | Hospitality | 2025 |
| Architectural Design and Planning Services Limited | Real estate | 1992 |
| Archnest Design Studio Ltd | Professional & scientific | 2024 |
| Archrose Wealth Management Limited | Financial services | 2026 |
| Arcmaster Limited | Wholesale & retail | 2012 |
| Arco (G.B.) Limited | Extraterritorial | 1985 |
| Arco Central Limited | Extraterritorial | 1986 |
| Arco Cleveland Limited | Extraterritorial | 1964 |
| Arco Group Limited | Extraterritorial | 1950 |
| Arco Holdings Limited | Extraterritorial | 1953 |
| Arco Hollman Nicholls Limited | Extraterritorial | 1951 |
| Arco Humberside Limited | Extraterritorial | 1946 |
| Arco Limited | Wholesale & retail | 1914 |
| Arco MTM Limited | Extraterritorial | 1979 |
| Arco Tyne and Wear Limited | Extraterritorial | 1957 |
| Arco West Midlands Limited | Extraterritorial | 1966 |
| Arctic REF Solutions Limited | Manufacturing | 2025 |
| Ardvark Electrical Limited | Energy | 2018 |
| Ares Security and Training Ltd | Financial services | 2025 |
| Arete Palace Limited | Wholesale & retail | 2025 |
| Arewa Luxury Limited | Wholesale & retail | 2024 |
| ARF Imperium Limited | Manufacturing | 2024 |
| ARF Prefabrication Ltd | Manufacturing | 2022 |
| ARH Modular Homes Ltd | Manufacturing | 2017 |
| ARH Portable and Modular Buildings Limited | Construction | 2012 |
| ARH Portable Buildings Limited | Manufacturing | 2023 |
| Aria Developments Yorkshire Ltd | Real estate | 2021 |
| Aria Inspection Services Ltd | Professional & scientific | 2023 |
| Ariadne Projects Limited | Information & communication | 2007 |
| Arigato Furniture Limited | Hospitality | 2021 |
| Arion Flow Ltd | Information & communication | 2025 |
| Ariss Properties Ltd | Households | 2021 |
| Arizona Continental Limited | Hospitality | 2024 |
| ARJ Contracting Services Limited | Professional & scientific | 2026 |
| ARJ Property Management (Hull) Ltd | Real estate | 2023 |
| ARK Alternative Education Provision Ltd | Education | 2024 |
| ARK Woodwork Ltd | Manufacturing | 2016 |
| ARK37 Ltd | Professional & scientific | 2024 |
| Arkani Limited | Real estate | 2025 |
| Arlington Moore Search and Selection Limited | Professional & scientific | 2005 |
| ARM Domestic Cleaning Limited | Other services | 2019 |
| ARM Signs Limited | Professional & scientific | 2016 |
| Arma Hydraulic Engineering Ltd. | Manufacturing | 1996 |
| Armak Ltd | Manufacturing | 2014 |
| Armante Couriers Limited | Transport & logistics | 2025 |
| Armed Forces & Veterans' Breakfast Clubs CIC | Health & social care | 2016 |
| Armitage Shanks Ltd | Manufacturing | 2003 |
| Armitage Washrooms Limited | Transport & logistics | 1934 |
| Armstrong Electrical (Hull) Limited | Administrative & support | 2017 |
| Armstrong Hydraulic Services (Hull) Limited | Manufacturing | 1985 |