| Alurim Automotive Limited | Wholesale & retail | 2019 |
| Amainiris Group Ltd | Wholesale & retail | 2020 |
| Ambergreen Services Ltd | Administrative & support | 2022 |
| Ampress Developments Limited | Construction | 2004 |
| Ampress Investments Ltd | Real estate | 2003 |
| Ampress Welding & Fabrications Limited | Manufacturing | 2004 |
| Anchor Land and Property Company Limited | Construction | 1972 |
| Anchor Stone Ltd | Financial services | 2001 |
| Ancient & Modern Builders Ltd | Manufacturing | 2024 |
| Andershaw Forest Limited | Agriculture & fishing | 2010 |
| Andy Davey Consulting Ltd | Other services | 2017 |
| Angel & Lockhart (Aviation) Ltd | Financial services | 2023 |
| Angel & Lockhart (Pharma) Ltd | Agriculture & fishing | 2018 |
| Angel & Lockhart (Transaction Services) Ltd | Information & communication | 2023 |
| Angel Hair Boutique Limited | Other services | 2011 |
| Angela Fitzhugh Public Relations Limited | Professional & scientific | 2000 |
| Angelic Celestial Colours Ltd | Wholesale & retail | 2019 |
| Anterion Ltd | Information & communication | 2024 |
| Anthony Lawrence Art Limited | Wholesale & retail | 2024 |
| Anthony Lawrence Lodge Limited | Real estate | 2024 |
| Anyday Software Ltd | Information & communication | 2021 |
| AON Services Ltd | Construction | 2024 |
| Appleby and Wood Consulting Limited | Professional & scientific | 1987 |
| Appletest Southern Region Limited | Professional & scientific | 2001 |
| Applied Radio Technology Limited | Information & communication | 2017 |
| Aqua Frome 2 LLP | | 2019 |
| Aqua Yachts Group Ltd | Manufacturing | 2019 |
| Aqua Yachts International Ltd | Arts & recreation | 2023 |
| Aquaire Limited | Arts & recreation | 2010 |
| Aquashore Limited | Real estate | 1993 |
| Aquaspec Limited | Wholesale & retail | 1995 |
| Aranya Expeditions Ltd | Administrative & support | 2026 |
| Arbor Venture Sales Ltd | Wholesale & retail | 2025 |
| Arbor Venture Tree Care Ltd | Agriculture & fishing | 2019 |
| Arbor-Venture Training Limited | Education | 2005 |
| Arbutus Group Ltd | Professional & scientific | 2024 |
| Archway Interior Design Limited | Construction | 2003 |
| Arek Garden Services Ltd | Administrative & support | 2024 |
| Argent Planning & Consulting Ltd | Professional & scientific | 2023 |
| Armada Contracting Group Ltd | Construction | 2023 |
| Arnewood Court (North) Management Company Limited | Real estate | 2013 |
| Arnewood Court Management Company Limited | Households | 1997 |
| Arrol Marina Consultancy Ltd | Professional & scientific | 2022 |
| Ashley & James Coachbuilding Limited | Manufacturing | 2016 |
| Ashley Clinton Manor Limited | Real estate | 1962 |
| Ashurst Developments (Colbury) Limited | Construction | 1988 |
| Asilvercloud Ltd | Real estate | 2019 |
| Asmediauk CIC | Information & communication | 2023 |
| Assisting Living Ltd | Construction | 2025 |
| Asteroidea Limited | Professional & scientific | 2019 |
| ASV Publishing Limited | Information & communication | 2020 |
| AT Retirement Services Ltd | Financial services | 2013 |
| Athey Consultancy (UK) Ltd | Professional & scientific | 2013 |
| Atlas Life Consulting Services Limited | Professional & scientific | 2019 |
| Aubretia Place Management Company Ltd | Real estate | 2025 |
| Aurum D Limited | Wholesale & retail | 2018 |
| Auto Skills Ltd | Professional & scientific | 2015 |
| Avanti Web Marketing Limited | Information & communication | 2009 |
| Avella Holdings Ltd | Manufacturing | 2016 |
| Aviation Selection Limited | Information & communication | 2006 |
| Avon Court Management Company Mudeford 2015 Limited | Households | 2015 |
| Avon Marina Holdings Limited | Financial services | 2019 |
| Avon Marina LLP | | 2020 |
| AW Parker Ltd | Administrative & support | 2022 |
| Azure Management Consulting Ltd | Professional & scientific | 2022 |
| B Assured Ltd | Construction | 2024 |
| Babelashampshire Ltd | Hospitality | 2026 |
| Baby Squids New Forest and Christchurch Ltd | Education | 2019 |
| Backtoback Theatre Company Limited | Arts & recreation | 2022 |
| Baker Classics Ltd | Professional & scientific | 2021 |
| Baker Crane Consulting Ltd | Professional & scientific | 2026 |
| Balkan Grill and Pizza Ltd | Hospitality | 2024 |
| Balloon Cloud New Forest Ltd | Wholesale & retail | 2021 |
| Barnard (Lymington) Ltd | Wholesale & retail | 2011 |
| Barnsland Properties Limited | Real estate | 2021 |
| Barry Frampton Limited | Construction | 2003 |
| Bass Charters Ltd | Administrative & support | 2017 |
| BAT TEN Electrical Contracting Services Limited | Extraterritorial | 2011 |
| Bath Freehold Limited | Real estate | 2023 |
| Battistinis Holding Group Limited | Other services | 2025 |
| Bay Tree Chiropractic Ltd | Health & social care | 2022 |
| Bbfi CIC | Administrative & support | 2008 |
| BBS Security Systems Limited | Administrative & support | 2000 |
| Bbuk Cars Limited | Wholesale & retail | 2016 |
| BCF Wessex Consultants Limited | Professional & scientific | 2011 |
| BCF Wessex Limited | Information & communication | 2014 |
| Beach Curd Limited | Wholesale & retail | 2024 |
| Beans & Paws Limited | Manufacturing | 2025 |
| Bear Data Ltd | Information & communication | 2017 |
| Beau's Health Limited | Wholesale & retail | 2018 |
| Beaulieu Bespoke Architectural Joinery Ltd | Manufacturing | 2024 |
| Beaumont Woolf Retail Limited | Real estate | 1986 |
| Beds on Board Limited | Hospitality | 2023 |
| Belco Holdings Limited | Real estate | 2009 |
| Belco Southern Limited | Real estate | 2009 |
| Belhaven KBB Limited | Wholesale & retail | 2009 |
| Bell & Mason Ltd | Other services | 2007 |
| Bellasea Ltd | Construction | 2022 |
| Bellerophon Consulting Ltd | Professional & scientific | 2014 |
| Bellwood (Dorset) Ltd | Information & communication | 2011 |