| Aghoco 2081 Limited | Financial services | 2021 |
| Aghoco 2082 Limited | Financial services | 2021 |
| Aghoco 2083 Limited | Financial services | 2021 |
| Agile People & Performance Ltd | Education | 2026 |
| AGL Films Limited | Information & communication | 2022 |
| Agnatel Limited | Information & communication | 2014 |
| Agog Moto Limited | Wholesale & retail | 2022 |
| Agog Vivid Limited | Professional & scientific | 2016 |
| AID Construction Ltd | Construction | 2019 |
| AIM High Accounts Limited | Professional & scientific | 2016 |
| AIM High Photography Ltd | Other services | 2008 |
| Air 2 Events Limited | Administrative & support | 2004 |
| Air and Fire Limited | Construction | 2018 |
| Airial Ltd | Professional & scientific | 2025 |
| Airvantage Drones Ltd | Professional & scientific | 2022 |
| Ajac Engineering Limited | Manufacturing | 2021 |
| Ajid Limited | Information & communication | 2017 |
| AJR Consultancy Solutions Limited | Professional & scientific | 2016 |
| AJS Motorcycles Limited | Wholesale & retail | 1979 |
| AK Grand Sales Limited | Wholesale & retail | 2018 |
| Akaina Consulting Limited | Professional & scientific | 2025 |
| Alanf Group Ltd | Professional & scientific | 2021 |
| ALB Specialists Ltd | Manufacturing | 2023 |
| Albedale Farms Limited | Agriculture & fishing | 1996 |
| Albion Tea Limited | Hospitality | 2014 |
| Aldelheidi's Blume Ltd | Wholesale & retail | 2021 |
| Alderstead Construction Limited | Construction | 2025 |
| Alderton Properties Ltd | Construction | 2011 |
| Alecstrans Ltd | Transport & logistics | 2011 |
| Alex Boldis Ltd | Transport & logistics | 2021 |
| Alex&Ama Trans Ltd | Transport & logistics | 2025 |
| Alexander Court Swanage Limited | Households | 2010 |
| Alexandrew Services Ltd | Health & social care | 2018 |
| ALI Stileman Ltd | Manufacturing | 2022 |
| Alignyourmind Ltd | Manufacturing | 2023 |
| Alikraft Holdings Limited | Financial services | 2022 |
| Alikraft Limited | Manufacturing | 2003 |
| ALL Metal Fabrications Engineering Limited | Administrative & support | 2010 |
| ALL Seasons Hire Limited | Administrative & support | 2006 |
| ALL the Write Stuff Limited | Information & communication | 2005 |
| All-Weather Bespoke Carpentry Limited | Manufacturing | 2019 |
| Allington Equine Ltd | Agriculture & fishing | 2015 |
| Almond Lettings Limited | Real estate | 2013 |
| Alnire Limited | Real estate | 2017 |
| Alota Dynasty Limited | Real estate | 2024 |
| Alpha Electrical Solutions Ltd | Professional & scientific | 2026 |
| Alpha Glazing Limited | Construction | 1998 |
| Alpha Sigma Partnerships Ltd | Professional & scientific | 2026 |
| Alpha Solar and Storage Ltd | Construction | 2024 |
| Alphabeauty Limited | Other services | 2023 |
| Alpine Group (1974) Limited | Manufacturing | 2008 |
| Alpine Group - Creative ORE LLP | | 2011 |
| ALR Hair Studio Limited | Other services | 2025 |
| ALS Laundry Limited | Administrative & support | 2023 |
| Alternative Fitness Solutions Ltd | Arts & recreation | 2008 |
| Alternative Flooring Holdings Limited | Financial services | 2019 |
| Altinel Construction Ltd | Construction | 2026 |
| Alumina Laser & Skin Ltd | Other services | 2025 |
| Alvistech Ltd | Real estate | 2014 |
| Always Inspire Consultancy Ltd | Professional & scientific | 2026 |
| Alyse Medcare Ltd | Health & social care | 2022 |
| AM 2 PM Plumbing and Tiling Services Limited | Construction | 2018 |
| Amanur Limited | Education | 2016 |
| Amasis Holdings Limited | Administrative & support | 2020 |
| Amasis Limited | Wholesale & retail | 2001 |
| Amber Desai Ltd | Information & communication | 2025 |
| Amber Marie Studio Ltd | Manufacturing | 2024 |
| Amcro Limited | Information & communication | 2008 |
| Amerleys Limited | Hospitality | 2024 |
| AMF Engineering Limited | Manufacturing | 2009 |
| Amport and District Coaches Limited | Wholesale & retail | 1997 |
| Amport Fields Management Company Limited | Real estate | 2014 |
| Amstart Properties Limited | Real estate | 2020 |
| AMY Broad Ltd | Professional & scientific | 2024 |
| Anchor Point Facilities Services Group Limited | Professional & scientific | 2026 |
| Anchored Hope Consultancy Ltd | Health & social care | 2022 |
| Andevx Ltd | Information & communication | 2019 |
| Andg Services Ltd | Information & communication | 2025 |
| Andon Design Consultants Limited | Professional & scientific | 2002 |
| Andover (T) Hairdressing Limited | Other services | 2004 |
| Andover Aesthetic Practitioners Ltd | Other services | 2018 |
| Andover B.I.D Limited | Professional & scientific | 2017 |
| Andover Business Computers Limited | Other services | 1995 |
| Andover Car Service Limited | Wholesale & retail | 2006 |
| Andover Castle Limited | Administrative & support | 2025 |
| Andover Catfe Ltd | Hospitality | 2023 |
| Andover Chiropractic Centre Ltd | Health & social care | 2005 |
| Andover Classic Motorcycle (Workshop) Ltd | Wholesale & retail | 1997 |
| Andover Community Services Limited | Arts & recreation | 2009 |
| Andover Community Sports LLP | | 2025 |
| Andover Convenience Store Ltd | Wholesale & retail | 2023 |
| Andover Domestic Plumbing & Heating Services Limited | Construction | 2023 |
| Andover Fire & Security Ltd | Administrative & support | 2016 |
| Andover Framing Limited | Arts & recreation | 2009 |
| Andover Garden Machinery Ltd | Wholesale & retail | 2009 |
| Andover GAS Engineers Ltd | Construction | 2015 |
| Andover Glass Works Limited | Construction | 1972 |
| Andover Golf Club Limited(The) | Arts & recreation | 1987 |
| Andover Groundworks & Construction Limited | Construction | 2016 |
| Andover Gym Club Limited | Arts & recreation | 1993 |