| Airey Investment Limited | Real estate | 2023 |
| Airey Property Management LLP | | 2023 |
| Airflex Logistics Limited | Transport & logistics | 2025 |
| Airtime Aviation Paint Ltd | Manufacturing | 2022 |
| AJ Cars Dorset Limited | Wholesale & retail | 2016 |
| AJ100.IQ Limited | Wholesale & retail | 2025 |
| Ajconsultation Ltd | Health & social care | 2021 |
| AJD Risk Management Consultancy Ltd | Professional & scientific | 2024 |
| AJW Partnership Ltd | Financial services | 2026 |
| AKO Dining Ltd | Hospitality | 2021 |
| Albab Corporation Ltd | Wholesale & retail | 2025 |
| Aldo Estate Limited | Real estate | 2020 |
| Alexander Chard Recruitment Ltd | Administrative & support | 2022 |
| Alexandra Dock Limited | Real estate | 2014 |
| Alexandra's Delights Ltd | Manufacturing | 2025 |
| Alibay-Mace Limited | Financial services | 2023 |
| Alice Watts Consulting Ltd | Professional & scientific | 2026 |
| Alii Drive Ltd | Professional & scientific | 2026 |
| Alii Drive Property Management Ltd | Real estate | 2026 |
| Alison Germain Limited | Administrative & support | 2015 |
| ALL Clear Electrical Services Ltd | Construction | 2008 |
| ALL Clear Energy Services Ltd | Construction | 2022 |
| ALL Counties Electrical Limited | Construction | 2013 |
| ALL Day Services Ltd | Transport & logistics | 2019 |
| ALL Holes and Patches Limited | Construction | 2023 |
| ALL Natural Landscaping Ltd | Administrative & support | 2026 |
| ALL Steps First Dance Ltd | Arts & recreation | 2018 |
| Allclean International Limited | Administrative & support | 2026 |
| Allcomms UK Ltd | Wholesale & retail | 2012 |
| Allegiant Web Services Ltd | Information & communication | 2021 |
| Allinone Professional Ltd | Construction | 2019 |
| Allsalt Maritime Europe Limited | Wholesale & retail | 2018 |
| Alltrista Plastics Limited | Manufacturing | 2000 |
| Alpha Omega Contracts Ltd | Construction | 2017 |
| Alpine Bliss Ltd | Hospitality | 2009 |
| Alternative Events Limited | Information & communication | 2016 |
| Altfin Solutions Limited | Administrative & support | 2019 |
| Altius Corporate Design and Build Limited | Financial services | 2001 |
| Ambergreen Properties Limited | Real estate | 2001 |
| AMC Electrical Services Limited | Construction | 2016 |
| Amcg Enterprise Limited | Hospitality | 2014 |
| Ameliorate Care Ltd | Extraterritorial | 2025 |
| American Continental Limited | Wholesale & retail | 2011 |
| American Fizz (UK) Limited | Wholesale & retail | 2011 |
| American Fizz Holdings Limited | Professional & scientific | 2016 |
| Amicis Brickwork Ltd | Construction | 2025 |
| Amjb Consultancy Ltd | Information & communication | 2013 |
| Ampress Electrical Contractors Ltd | Construction | 2018 |
| AMV News Limited | Wholesale & retail | 2019 |
| Anderson Global Business Ltd | Construction | 2022 |
| Anderwood Homes Ltd | Construction | 2024 |
| Andrew Brown Funeral Directors Ltd | Other services | 2026 |
| Andrew M Higgs & Co Limited | Financial services | 2017 |
| Andrews & Brunt Ltd | Professional & scientific | 2017 |
| Animal Osteopathy International Limited | Wholesale & retail | 2020 |
| Animals at Home (Bournemouth & New Forest) Ltd | Other services | 2012 |
| Anthony Carpentry & Building Services Limited | Construction | 2006 |
| AOG Worldwide Ltd | Administrative & support | 2009 |
| APE Broadcast Ltd | Information & communication | 2019 |
| Apex Holdings Southern Limited | Financial services | 2018 |
| Apex Soil Solutions Limited | Agriculture & fishing | 2018 |
| Apex Tool Solutions Limited | Wholesale & retail | 2017 |
| Apex Tree Surgeons Limited | Agriculture & fishing | 2012 |
| App Parking (Gillingham) Ltd | Real estate | 2025 |
| App Parking Ltd | Real estate | 2024 |
| Apple House Projects Limited | Real estate | 2001 |
| Apple Tree Gardens Limited | Households | 2020 |
| April Breeze Limited | Real estate | 2025 |
| AQP Limited | Real estate | 2016 |
| Aqua Luxury Nail & Beauty Ltd | Other services | 2026 |
| Aquapura Ltd | Professional & scientific | 2022 |
| Aquatrader Group Limited | Wholesale & retail | 2023 |
| Arbor Close (Highcliffe) Management Limited | Households | 2020 |
| Arcevolve Ltd | Health & social care | 2025 |
| Archelles Consulting Ltd | Professional & scientific | 2020 |
| Archrest Limited | Construction | 2024 |
| Archway Capital Holdings Limited | Real estate | 1996 |
| Archway Capital Limited | Extraterritorial | 2019 |
| Ardshiel Properties LLP | | 2010 |
| ARI Consultants Ltd | Professional & scientific | 2023 |
| Arian Consulting Ltd | Financial services | 2013 |
| Arik Design and Development Limited | Construction | 2008 |
| Aris House Management Company Limited | Households | 2023 |
| Arken Capital Limited | Construction | 2016 |
| Arken Homes Limited | Construction | 2016 |
| Arnold Accounting & Bookkeeping Services Ltd | Professional & scientific | 2016 |
| Aroma Builders Limited | Construction | 2018 |
| Art Holidays GB Ltd | Arts & recreation | 2013 |
| Arteca Ltd | Wholesale & retail | 2025 |
| Artemis Ecological Consulting Limited | Professional & scientific | 2015 |
| Artisan Theatre School Limited | Education | 2024 |
| AS Enterprises (Bournemouth) Ltd | Administrative & support | 2023 |
| Asana Tree Limited | Wholesale & retail | 2019 |
| Asbestos Safety Solutions Limited | Administrative & support | 2014 |
| ASG UK Distribution Limited | Wholesale & retail | 2026 |
| Asgard Cleaning & Maintenance Ltd | Administrative & support | 2024 |
| Asgun Ltd | Wholesale & retail | 2014 |
| Asgun Property Ltd | Real estate | 2025 |
| Ashbourne Court Limited | Real estate | 2008 |
| Ashley Arnewood Co Ltd | Households | 2025 |