| Astoria Ironmongery Limited | Wholesale & retail | 2019 |
| AT the Station Limited | Hospitality | 2024 |
| Atelier Kaizen Ltd | Wholesale & retail | 2025 |
| Athena (Beauty and Nails) Ltd | Other services | 2013 |
| Athos Limited | Professional & scientific | 2015 |
| Atkar Properties Ltd | Real estate | 2021 |
| Atkin Solutions Limited | Construction | 2017 |
| Atlantic Cleaning Solutions Limited | Administrative & support | 2019 |
| Atlas Books (Global) Limited | Extraterritorial | 2023 |
| Atmg Limited | Information & communication | 2025 |
| ATS Recovery Ltd | Wholesale & retail | 2025 |
| Atticus Connect Limited | Information & communication | 2017 |
| Atticus Resources Limited | Professional & scientific | 2017 |
| ATW Haulage Limited | Transport & logistics | 2001 |
| Auto Maintenance Weymouth Limited | Wholesale & retail | 2010 |
| Automation Consulting Limited | Information & communication | 2007 |
| Automek Services Limited | Wholesale & retail | 2001 |
| Autonomous Investments (Media Strategy and Experience Management) Limited | Other services | 2009 |
| AVA Property Management Ltd | Real estate | 2021 |
| Avix Aviation Services Ltd | Professional & scientific | 2014 |
| Avlm Group Limited | Administrative & support | 2022 |
| Avon LEA Weymouth 2015 Limited | Health & social care | 2015 |
| Avro Associates Ltd | Other services | 2012 |
| Avro Yachting Limited | Arts & recreation | 2014 |
| AW Trucks Ltd | Transport & logistics | 2024 |
| AWR Drivers Ltd | Transport & logistics | 2023 |
| Axiom CSG Limited | Administrative & support | 2010 |
| Axium Centre Management Limited | Households | 2007 |
| AXL Management Ltd | Administrative & support | 2019 |
| Ayome Groceries Ltd | Wholesale & retail | 2025 |
| Azimuth One Limited | Professional & scientific | 2013 |
| Azur Sea 30 Ltd | Hospitality | 2026 |
| Azure Limited | Information & communication | 1990 |
| B a Gosney Ltd | Construction | 2015 |
| B a Wellburn Limited | Wholesale & retail | 2018 |
| B Camuk Ltd. | Construction | 2015 |
| B Rossiter Building Services Limited | Construction | 2003 |
| B T Churchill Limited | Construction | 2002 |
| Baboo Gelato Ltd. | Manufacturing | 2013 |
| Baby WE Care Limited | Wholesale & retail | 2017 |
| Back in Touch Limited | Health & social care | 2009 |
| Bageri Limited | Hospitality | 2022 |
| Baima Media Ltd | Wholesale & retail | 2020 |
| Baking Soda Productions Limited | Health & social care | 2017 |
| Balidon House Management Company Limited | Households | 2011 |
| Balmoor Properties Limited | Construction | 2024 |
| Balmoral Flats Management Company Limited | Hospitality | 1997 |
| Baltrunas & Co Limited | Information & communication | 2019 |
| Bamlea Ltd | Wholesale & retail | 2026 |
| Bammas Cafe Co Ltd | Hospitality | 2018 |
| Bankes Court RTM Management Company Limited | Households | 2021 |
| Banyard Group Limited | Construction | 2004 |
| Baratro Consulting Limited | Professional & scientific | 2014 |
| Barbe & Bald Limited | Manufacturing | 2002 |
| Barco Construction Ltd | Construction | 2012 |
| Barcraft (Devon) Limited | Hospitality | 2024 |
| Bardolf Farms Limited | Agriculture & fishing | 1963 |
| Bare Kitchens Limited | Wholesale & retail | 2024 |
| Barley Future Ltd | Real estate | 2022 |
| Barleycorn Blue (GP) Limited | Real estate | 2012 |
| Barnhaven Farm Limited | Administrative & support | 2015 |
| Bartec Consultancy Limited | Professional & scientific | 2003 |
| Barton Lodge (Cerne Abbas) Management Limited | Households | 2006 |
| Barty Murphy & Thomas Ltd | Real estate | 2010 |
| Barwick Music Ltd | Wholesale & retail | 2000 |
| Basilico Simply Italian Limited | Hospitality | 2024 |
| Bassenhall (Jesmond) Management Limited | Extraterritorial | 1996 |
| Bathroom Spares Ltd | Administrative & support | 2017 |
| BC Visuals Ltd | Information & communication | 2019 |
| Bchl Investments Limited | Professional & scientific | 2017 |
| Beach Castle Cafe Limited | Hospitality | 2017 |
| Beachspring Limited | Agriculture & fishing | 1997 |
| Beacon Coast Design & Development Ltd | Professional & scientific | 2006 |
| Beaconville Healthcare Limited | Administrative & support | 2018 |
| Beale Heating LLP | | 2002 |
| Bear Business Limited | Professional & scientific | 2014 |
| Bear Investments Ltd | Real estate | 2022 |
| Beaulieu Property Management Limited | Real estate | 1990 |
| Beaumont Life Limited | Health & social care | 2024 |
| Becks Building Ltd | Construction | 2026 |
| Bedfordshire Land Promotions Ltd | Administrative & support | 2015 |
| Bedroom Ideas Limited | Construction | 1990 |
| BEE Housings Ltd | Construction | 2023 |
| Bee's Knees Bakes Ltd | Wholesale & retail | 2023 |
| Beecause... Ltd | Wholesale & retail | 2025 |
| Beech Farm Ltd | Agriculture & fishing | 2012 |
| Beech Farm Trading Limited | Agriculture & fishing | 2014 |
| Beechtop RTM Company Limited | Real estate | 2007 |
| Beechwood Lane Management Company Limited | Households | 2010 |
| Beehive Investment Holdings Limited | Financial services | 2020 |
| Beetle Magic Limited | Wholesale & retail | 2012 |
| Bell Family Mallorca Properties UK Limited | Professional & scientific | 2025 |
| Belle Civils and Groundworks Ltd | Construction | 2025 |
| Belle Civils Limited | Construction | 2022 |
| Belle Construction Dorset Limited | Construction | 2007 |
| Belle VUE Court(Weymouth)Limited | Households | 1965 |
| Belx Limited | Extraterritorial | 2003 |
| Bemacross Contractors Limited | Construction | 2001 |
| BEN Clarke Racing Limited | Arts & recreation | 2020 |
| BEN Howell Financial Limited | Financial services | 2015 |