| Avocet Horizons Limited | Information & communication | 2013 |
| AWR Lettings Ltd | Real estate | 2025 |
| Aztek Travel Ltd | Transport & logistics | 2016 |
| Azur Innovation Limited | Professional & scientific | 2008 |
| Azzurra Aviation Limited | Other services | 2024 |
| B B Plastics Ltd. | Manufacturing | 2008 |
| B Hayes Limited | Households | 2010 |
| B R Clift Limited | Construction | 2000 |
| B R Marine (UK) Limited | Administrative & support | 2013 |
| B Stunning Limited | Wholesale & retail | 2022 |
| B the One Ltd | Wholesale & retail | 2021 |
| B&P Land & Property Limited | Real estate | 2024 |
| B&W Capital Ltd | Professional & scientific | 2021 |
| Baan 57 Ltd | Wholesale & retail | 2017 |
| Baazargai Limited | Construction | 2023 |
| Babs & Festa Limited | Other services | 2022 |
| Baby Birds Limited | Wholesale & retail | 2006 |
| Baby Birds Wellness Ltd | Wholesale & retail | 2022 |
| Babylon Hair & Beauty Ltd | Real estate | 2021 |
| Bacaro Weymouth Limited | Hospitality | 2024 |
| Baker Joinery Ltd | Manufacturing | 2011 |
| Bakery Direct Limited | Wholesale & retail | 2011 |
| Balem Investments Limited | Professional & scientific | 2022 |
| Ballak Limited | Hospitality | 2025 |
| Ballycuan Inns Ltd | Hospitality | 2018 |
| Balti Dorset Ltd | Hospitality | 2016 |
| Bamboo for Home and Office Limited | Wholesale & retail | 2015 |
| Banaoth Ltd | Wholesale & retail | 2024 |
| Bandit & B Limited | Wholesale & retail | 2019 |
| Banks Property Services Limited | Real estate | 2015 |
| Bar Acqua Limited | Hospitality | 2012 |
| Bar Runners Ltd | Transport & logistics | 2019 |
| Barbers Lounge Limited | Other services | 2006 |
| Barefacebydest Ltd | Other services | 2024 |
| Barker Hospitality Ltd | Hospitality | 2021 |
| Barlow House Leasehold 57 Ltd | Real estate | 2025 |
| Barnes-Ward Limited | Financial services | 2001 |
| Barnett Safety Services Ltd | Extraterritorial | 2012 |
| Barnhayes Farm Limited | Agriculture & fishing | 2019 |
| Barnsley Models and Games Ltd | Other services | 2014 |
| Barracuda (Dorset) Limited | Wholesale & retail | 2016 |
| Barrett Enterprises (Dorset) Limited | Construction | 2015 |
| Barretts Electrical (Dorset) Limited | Construction | 2020 |
| Barry Evans (Fibre Optics) Limited | Administrative & support | 2004 |
| Barry's Coaches Limited | Transport & logistics | 1973 |
| Bartlett's Carpets & Flooring Ltd | Wholesale & retail | 2026 |
| Bartletts South West Ltd | Wholesale & retail | 2001 |
| Bassett Holdings (SW) Limited | Professional & scientific | 2010 |
| Bassett Retail Limited | Wholesale & retail | 2012 |
| Bay Engineering Dorset Limited | Manufacturing | 2001 |
| Bay Trees (Weymouth) Management Company Limited | Administrative & support | 2009 |
| Bay Watch Management Limited | Households | 1986 |
| Bayliss Hall Limited | Hospitality | 2025 |
| Baywey Limited | Households | 2002 |
| BBF Property Group Limited | Real estate | 2023 |
| BCM Plumbing & Heating Solutions Ltd | Construction | 2022 |
| BD Logistics Ltd | Wholesale & retail | 2019 |
| Beach and Bay Building Ltd | Construction | 2021 |
| Beach Court (Weymouth) Limited | Households | 1981 |
| Beach Life Cams Limited | Information & communication | 2024 |
| Beacon Financial Solutions Limited | Financial services | 2001 |
| Bear With ME Limited | Information & communication | 2012 |
| Beau Living Ltd | Real estate | 2025 |
| Beaufort Garden Mews RTM Company Limited | Households | 2010 |
| Beaumont Estates (Yeovil) Limited | Real estate | 2007 |
| Beaumont Jones Estate Agents Limited | Real estate | 2024 |
| Beaumont Jones Lettings Ltd | Real estate | 2026 |
| Beech Close Dorchester Management (1969) Limited | Households | 1969 |
| BEI Thermal Ltd | Construction | 2022 |
| BEL Solutions Limited | Other services | 2006 |
| Belben Consulting Ltd | Professional & scientific | 2015 |
| Bell Percussion Limited | Administrative & support | 1987 |
| Bella Ceramics Limited | Arts & recreation | 2016 |
| Bella Kitchens and Bathrooms Ltd | Financial services | 2022 |
| Belle Technology UK Ltd | Manufacturing | 2009 |
| Belle VUE Solutions Limited | Professional & scientific | 2022 |
| Belle's Traditional Bakers Limited | Hospitality | 2014 |
| Belvidere House (Management) Limited | Households | 2019 |
| Belvidere House Limited | Real estate | 2001 |
| BEN Rogers Marketing Ltd | Professional & scientific | 2026 |
| Bennetts Water Gardens Ltd | Extraterritorial | 2014 |
| Berkeley Restaurant (Weymouth) Limited | Real estate | 1951 |
| Berry and Berry Business Ltd | Hospitality | 2023 |
| Berry Hill Estates Ltd | Construction | 2021 |
| Berry's Bakery Limited | Manufacturing | 2019 |
| Bertram Property Managers (Weymouth) Limited | Households | 1976 |
| BES Electrical (Dorset) Limited | Construction | 2013 |
| Bespoke Campervan Competitions Ltd | Manufacturing | 2025 |
| Bespoke Hairdressing Training Limited | Education | 2015 |
| Bespoke Integration Limited | Information & communication | 2008 |
| Bespoke Paint and Body Limited | Wholesale & retail | 2017 |
| Bespoke Training Club Limited | Education | 2024 |
| Best Plans Ltd | Extraterritorial | 2021 |
| Betterment Development Limited | Construction | 2021 |
| Betterment Properties (Weymouth) Limited | Construction | 1967 |
| Bettles Court Freehold Limited | Households | 2015 |
| Bevington Garages Ltd | Real estate | 2022 |
| Bevington Motors Limited | Wholesale & retail | 2012 |
| Bevington Software Ltd | Information & communication | 2025 |
| Bexlie Wealth Management Limited | Professional & scientific | 2022 |