| Appleby Frodingham Works Athletic Club Limited | Administrative & support | 2009 |
| Appleby Property Services Limited | Construction | 2008 |
| Appleby-Frodingham Cottage Trust Limited | Hospitality | 1936 |
| Applegate Consulting Ltd | Information & communication | 2009 |
| Applied Business Solutions UK Ltd | Real estate | 1996 |
| Approved Door Consultancy Ltd | Construction | 2023 |
| Approved Housing Ltd | Real estate | 2022 |
| Approved Supplies Ltd | Wholesale & retail | 2022 |
| Appt-Bookings Ltd | Information & communication | 2026 |
| APT Aesthetics Limited | Health & social care | 2011 |
| APT Business Solutions Limited | Construction | 2023 |
| Apty Medical Ltd | Professional & scientific | 2024 |
| APX Digital Ltd | Professional & scientific | 2025 |
| Aquanauts Swimming Academy Ltd | Education | 2013 |
| Aquanauts Swimming Limited | Education | 2014 |
| Arabella Bespoke Interiors Limited | Professional & scientific | 2019 |
| Aras Top Repairs Ltd | Construction | 2026 |
| Arbs Retail Ltd | Hospitality | 2024 |
| ARC Developments (NE) Ltd | Real estate | 2021 |
| ARC Electrical Solutions (NE) Ltd | Construction | 2019 |
| Arch and IVY Limited | Information & communication | 2015 |
| Architectural Design Services (Scunthorpe) Limited | Professional & scientific | 2000 |
| Arcos Global Limited | Wholesale & retail | 2015 |
| Arcos Transmedia Limited | Professional & scientific | 2017 |
| ARG Tools Limited | Real estate | 1976 |
| Arialtrail Ltd | Arts & recreation | 2015 |
| Ariana Ltd | Wholesale & retail | 2025 |
| Arif Medical Limited | Health & social care | 2021 |
| Arin 285 Ltd | Hospitality | 2025 |
| Arise Jppb Limited | Health & social care | 2011 |
| ARJ Health Limited | Health & social care | 2015 |
| ARK Properties (Spalding) Limited | Construction | 2004 |
| Arma Distribution Ltd | Transport & logistics | 2020 |
| Arminta Ltd | Wholesale & retail | 2019 |
| Aros Legacy Ltd | Wholesale & retail | 2025 |
| Arrow Clothing Ltd | Wholesale & retail | 2024 |
| Arrow Engineering Holdings Limited | Professional & scientific | 2009 |
| ARS Heartscan Services Limited | Health & social care | 2023 |
| Art-Tom Trans Ltd | Transport & logistics | 2026 |
| Arthi Limited | Health & social care | 2019 |
| Articulus Medical Limited | Health & social care | 2024 |
| Artisandra Limited | Agriculture & fishing | 2018 |
| Artolive Ltd | Wholesale & retail | 2025 |
| Artom Autos Ltd | Wholesale & retail | 2017 |
| Arturito Ltd | Manufacturing | 2020 |
| Artwurcs Limited | Manufacturing | 2020 |
| As-Salam Arabic School Ltd | Education | 2026 |
| Asar Diagnostics Ltd | Health & social care | 2016 |
| Asbury Study Abroad Ltd | Administrative & support | 2021 |
| Ascension Access Ltd | Other services | 2025 |
| Ascross Ltd | Professional & scientific | 2021 |
| Asdi Properties Limited | Real estate | 2021 |
| ASE Investments Limited | Professional & scientific | 2002 |
| Asero Ltd | Professional & scientific | 2021 |
| ASH and ELM Woodworks Ltd | Manufacturing | 2026 |
| ASH Taxis Limited | Transport & logistics | 2018 |
| ASH View Services Limited | Professional & scientific | 2001 |
| ASH Zach Ltd | Administrative & support | 2020 |
| Ashadeep Limited | Real estate | 2011 |
| Ashby Aquatics Ltd. | Wholesale & retail | 2019 |
| Ashby Auto Care Ltd | Wholesale & retail | 2023 |
| Ashby Carpets & Vinyls Ltd | Wholesale & retail | 2026 |
| Ashby Cars Ltd | Wholesale & retail | 2021 |
| Ashby GAS Services (Scunthorpe) Ltd | Construction | 2013 |
| Ashby GAS Services Commercial Limited | Construction | 2022 |
| Ashby One Ltd | Transport & logistics | 2024 |
| Ashby One Taxis Ltd | Transport & logistics | 2026 |
| Ashby Pizza Ltd | Hospitality | 2025 |
| Ashby Postal Bird Ltd | Transport & logistics | 2025 |
| Ashodesigns Limited | Professional & scientific | 2025 |
| Ashville Property Investments Ltd | Real estate | 2025 |
| Asian Persuasion Ltd | Hospitality | 2021 |
| ASK Paul's Plumbing Services Limited | Construction | 2011 |
| ASL Property (Holdings) Ltd | Real estate | 2024 |
| ASL Property Development & Services Ltd | Construction | 2024 |
| ASL Welding Ltd | Manufacturing | 2010 |
| ASP Recruit Ltd | Other services | 2018 |
| Aspire KH Ltd | Real estate | 2020 |
| Asset Drone Inspection Ltd | Extraterritorial | 2023 |
| Assured Agronomy Ltd | Agriculture & fishing | 2014 |
| ASU Couriers Ltd | Transport & logistics | 2026 |
| Atcs Holdings Limited | Financial services | 2024 |
| Athanasias Medical & Surgical Limited | Health & social care | 2017 |
| Athena Bakery Ltd | Hospitality | 2025 |
| Athena Financial Services Ltd | Professional & scientific | 2011 |
| Athena Holdings Ltd | Professional & scientific | 2009 |
| Athena the Original Greek Food Ltd | Hospitality | 2025 |
| Athenas the Original Greek Food Ltd | Hospitality | 2026 |
| Atkin Transport Limited | Transport & logistics | 2010 |
| Atlantis Consultants Ltd | Professional & scientific | 2024 |
| Atlas TCG Limited | Wholesale & retail | 2025 |
| Atrium - Businesses for the Community Ltd | Administrative & support | 2025 |
| Attendance Matters Limited | Education | 2014 |
| Atwell Properties Ltd | Manufacturing | 2023 |
| AUH (Estates) Ltd | Real estate | 2026 |
| Aun-Tea Ltd | Hospitality | 2025 |
| Aurelia Nistor Ltd | Transport & logistics | 2025 |
| Aurimas Transport Ltd | Transport & logistics | 2024 |
| Auris Transport Ltd | Transport & logistics | 2018 |
| Aurora Payroll Services Limited | Professional & scientific | 2024 |