| Andrei MD Ltd | Administrative & support | 2019 |
| Andrei Strainu Limited | Transport & logistics | 2018 |
| Andreialexandra Trans Ltd | Transport & logistics | 2025 |
| Andrew Ashwin Limited | Information & communication | 2014 |
| Andrew LEE Home and Living Ltd | Manufacturing | 2019 |
| Andron Services Limited | Transport & logistics | 2016 |
| Andrzej Fraszczak Limited | Transport & logistics | 2020 |
| ANDRZEJ88 Limited | Wholesale & retail | 2026 |
| Anecosmetics Ltd | Wholesale & retail | 2024 |
| Ang's Skin LAB Ltd | Other services | 2026 |
| Angel-Maxincia Clothing Ltd | Wholesale & retail | 2018 |
| Angel-Maxincia Mental Health Limited | Health & social care | 2018 |
| Angelica Salimo Recruitment Limited | Administrative & support | 2023 |
| Angies Place Ltd | Other services | 2016 |
| Anglian Grounds Maintenance and Landscaping Ltd | Construction | 2026 |
| Anglo Denton Solar Ltd | Professional & scientific | 2021 |
| Anglo Energy Storage Ltd | Professional & scientific | 2021 |
| Anglo ES Awbridge Farm Ltd | Professional & scientific | 2023 |
| Anglo ES Bean Lane Ltd | Professional & scientific | 2022 |
| Anglo ES Berkswell Ltd | Professional & scientific | 2022 |
| Anglo ES Easter Compton Limited | Professional & scientific | 2024 |
| Anglo ES Great Wyrley Ltd | Professional & scientific | 2022 |
| Anglo ES Hams Hall Ltd | Professional & scientific | 2021 |
| Anglo ES Kitwell Ltd | Professional & scientific | 2021 |
| Anglo ES Larks Lane Ltd | Professional & scientific | 2022 |
| Anglo ES Levedale Ltd | Professional & scientific | 2021 |
| Anglo ES Nursling Ltd | Professional & scientific | 2021 |
| Anglo ES Oaksey Ltd | Professional & scientific | 2022 |
| Anglo ES Says Court Ltd | Professional & scientific | 2021 |
| Anglo ES Water Orton Ltd | Professional & scientific | 2021 |
| Anglo ES Whites Farm Ltd | Professional & scientific | 2021 |
| Anglo Renewables Ltd | Energy | 2020 |
| Animalier Ltd | Transport & logistics | 2018 |
| Anis UN Limited | Health & social care | 2025 |
| Annie Benedicto Recruitment Limited | Administrative & support | 2022 |
| Anro Construction Ltd | Construction | 2019 |
| Antevasin Group Limited | Wholesale & retail | 2022 |
| Anthony Healthcare Ltd | Administrative & support | 2023 |
| Anthony Transport Ltd | Transport & logistics | 2017 |
| Antihero Social Media Ltd | Information & communication | 2025 |
| Antiquus Ltd | Wholesale & retail | 2025 |
| Antonczak Transport Ltd | Transport & logistics | 2020 |
| AO Refrigeration and Heat Pump Renewable Ltd | Construction | 2022 |
| AP Site Services Limited | Professional & scientific | 2020 |
| AP Stewart Ltd | Information & communication | 2026 |
| Apex Glass Limited | Construction | 2004 |
| Apex Racing UK Ltd | Information & communication | 2016 |
| Apexxe Holdings Ltd | Financial services | 2025 |
| Apia Trans Ltd | Transport & logistics | 2017 |
| Apms Transport Ltd | Other services | 2018 |
| APN Services Limited | Administrative & support | 2024 |
| Apollonia Care Services Ltd | Health & social care | 2024 |
| Apollos Recruitment Agency Limited | Administrative & support | 2008 |
| Appexi Services Limited | Real estate | 2022 |
| Appraising Company Ltd | Other services | 2018 |
| APW & SPM Engineering Services Limited | Construction | 2003 |
| Aqua-Gas Manufacturing Limited | Manufacturing | 1983 |
| AR Global Events (UK) Ltd | Arts & recreation | 2024 |
| AR Kingsclere Ltd | Administrative & support | 2022 |
| AR Moulding Limited | Financial services | 2026 |
| Aram Haircuts Ltd | Other services | 2024 |
| Arbury Electrical Services Ltd | Manufacturing | 2022 |
| Arbury Hill Limited | Other services | 2021 |
| Arbury Precision Engineering Ltd | Manufacturing | 2022 |
| Arbury Refrigeration Engineering Limited | Extraterritorial | 2022 |
| Arbury Stone Products Limited | Manufacturing | 2023 |
| Arch Media Productions Limited | Arts & recreation | 2025 |
| Architile Ltd | Construction | 2020 |
| Archway Property Ltd | Real estate | 2012 |
| Arcrite (GB) Limited | Manufacturing | 2007 |
| Arctic Drift Refrigeration Ltd | Manufacturing | 2018 |
| Arcus Surveys and Engineering Ltd | Construction | 2012 |
| Arden Shop Limited | Wholesale & retail | 2025 |
| Arek Repair Car Ltd | Wholesale & retail | 2025 |
| Argf Limited | Health & social care | 2011 |
| ARK Engineering Ltd | Manufacturing | 2021 |
| Arkle Management Consultancy Limited | Administrative & support | 2013 |
| Arkle Property Limited | Real estate | 2022 |
| Arluni Limited | Professional & scientific | 2026 |
| Armaan Patel Limited | Hospitality | 2008 |
| Arqen Holdings Ltd | Financial services | 2025 |
| Art Computer Consultancy Ltd | Information & communication | 2000 |
| Artemis (Brightlingsea) Ltd | Construction | 2022 |
| Artemis Brightlingsea NO. 2 Limited | Professional & scientific | 2022 |
| Artemis Capital Partners Ltd | Professional & scientific | 2021 |
| Artemis Leisure Management Limited | Professional & scientific | 2022 |
| Arthur Francis Sculpture Limited | Manufacturing | 2020 |
| Artorius Flexographic Ltd | Manufacturing | 2024 |
| Artur Trans Ltd | Transport & logistics | 2015 |
| Asbestoglide Limited | Construction | 2014 |
| Ascot Residential Property Holdings Limited | Real estate | 2024 |
| Aseomotors Ltd | Wholesale & retail | 2020 |
| Asesa Solutions Ltd | Professional & scientific | 2019 |
| Ashbrook Rees Ltd | Financial services | 2015 |
| Ashfield Consultancy Ltd. | Health & social care | 2014 |
| Ashley 1959 Limited | Extraterritorial | 2013 |
| ASK Management Solutions Ltd | Real estate | 2024 |
| Aspire - Cognitive Behavioural Therapy Practice Ltd | Health & social care | 2013 |
| Aspire Parks Limited | Real estate | 2010 |
| Assist Quality Ltd | Professional & scientific | 2011 |