| BEN Pine Electrical Limited | Construction | 2013 |
| Bennett Brothers Properties Limited | Real estate | 2024 |
| Bennett's Campsite Fish & Chips Limited | Hospitality | 2017 |
| Bennett's Mobile Seafood Catering Limited | Hospitality | 2012 |
| Benrage Limited | Construction | 1995 |
| Benridge Investments Limited | Real estate | 2000 |
| Benville Manor Camping Limited | Other services | 2021 |
| Bepo Gelato Ltd | Wholesale & retail | 2023 |
| Bere Regis MOT Centre Limited | Wholesale & retail | 2019 |
| Berkeley Hotel (Dorset) Limited | Hospitality | 2002 |
| Bernard COX Limited | Agriculture & fishing | 2003 |
| Bernard Walsh and Co Ltd | Professional & scientific | 2014 |
| Bernard Walsh Consultants Ltd | Information & communication | 2012 |
| Bespoke Leather Limited | Manufacturing | 2011 |
| Bespoke Publishing Limited | Information & communication | 2006 |
| Best Kept Books and Consultancy Ltd | Professional & scientific | 2022 |
| Best Price Hearing Aids Limited | Wholesale & retail | 2020 |
| Better Care at Home Limited | Health & social care | 2015 |
| Better Care at Home West Limited | Health & social care | 2020 |
| Better on Ltd | Manufacturing | 2021 |
| BG Assessors Ltd | Professional & scientific | 2025 |
| Bhompston Management Limited | Households | 1996 |
| Bickleigh Limited | Wholesale & retail | 1997 |
| BID Artificially Intelligent Robotics Ltd. | Information & communication | 2004 |
| BID Perfect Limited | Administrative & support | 2007 |
| Bielec Consultancy Limited | Professional & scientific | 2021 |
| Big Bear Apparel Ltd | Manufacturing | 2018 |
| Big Effort Limited | Professional & scientific | 2007 |
| Bigtide Ltd | Information & communication | 2022 |
| Bionkor Health Ltd | Professional & scientific | 2024 |
| Birchwood Renewables Limited | Energy | 2015 |
| Bird Media Ltd | Information & communication | 2022 |
| Bizkit-Tin Ltd | Financial services | 2023 |
| Bizpro Ltd | Wholesale & retail | 2018 |
| Blackburn Law Limited | Professional & scientific | 2012 |
| Blacknoll Construction Limited | Real estate | 1994 |
| Blacknoll Holdings Limited | Financial services | 2023 |
| Bladen Valley Nursery Ltd | Agriculture & fishing | 2018 |
| Blandford Heating Limited | Construction | 2023 |
| Blandford Revival Ltd | Real estate | 2025 |
| Blazeminster Limited | Construction | 1996 |
| Block G1B Poundbury Dorchester Management Limited | Households | 2008 |
| Blocksure Limited | Information & communication | 2016 |
| BLU Holdings Limited | Information & communication | 2016 |
| Blue Bowl Ltd | Wholesale & retail | 2015 |
| Blue C Ltd | Construction | 2023 |
| Blue Dolphin Capital Ltd | Financial services | 2025 |
| Blue Dolphin Medical Ltd | Health & social care | 2025 |
| Blue Dolphin Welfare Ltd | Health & social care | 2025 |
| Blue Ghost Limited | Wholesale & retail | 2023 |
| Blue Hedgehog Display Limited | Administrative & support | 2002 |
| Blue Horse Equine Limited | Wholesale & retail | 2005 |
| Blue Line Studios Ltd | Information & communication | 2025 |
| Blue Majic Ltd | Information & communication | 2019 |
| Blue Tongue Projects Ltd. | Manufacturing | 2019 |
| Bluebells Nursery School (JK) Limited | Education | 2010 |
| Blueberry Adviser Academy Limited | Financial services | 2019 |
| Blueberry Estate Planning Limited | Financial services | 2017 |
| Blueberry Wealth Limited | Financial services | 2013 |
| Bluebird Construction & Management Limited | Construction | 2022 |
| Bluecity Limited | Construction | 2012 |
| Bluefish Cafe and Restaurant Limited | Hospitality | 2010 |
| Bluewood Asset Management Ltd | Real estate | 2023 |
| BLW Poundbury Ltd | Other services | 2026 |
| Boathouse Maintenance Limited | Administrative & support | 2003 |
| BOB Gallienne Consulting Ltd | Administrative & support | 2012 |
| Bodan Workshops Limited | Administrative & support | 2014 |
| Bodark Ltd | Real estate | 2026 |
| Boiler Merchant Limited | Wholesale & retail | 2018 |
| Boiler Servicing Limited | Manufacturing | 2018 |
| Boilerman Limited | Construction | 2000 |
| Boilermen Limited | Professional & scientific | 2005 |
| Bolton Resourcing Limited | Administrative & support | 1997 |
| Bonjour Poundbury Ltd | Hospitality | 2023 |
| Bonnie 1 Limited | Professional & scientific | 2012 |
| Booboo and Squirt Limited | Wholesale & retail | 2009 |
| Booly Holdings Limited | Financial services | 2025 |
| Booze Box Dorset Limited | Hospitality | 2020 |
| Bosswood Limited | Manufacturing | 2015 |
| Bosworth Boating Ltd | Professional & scientific | 2026 |
| Bosworth Care Home (Dorset) Ltd | Health & social care | 2015 |
| Bournemouth Aviation Charitable Foundation | Arts & recreation | 1994 |
| Bournemouth House Purchase Company Limited | Construction | 1955 |
| Bournemouth Steel Limited | Wholesale & retail | 2018 |
| Bowden Farm Services Limited | Agriculture & fishing | 2002 |
| Bowerstock Limited | Real estate | 1989 |
| Bowman B and E Consultants Ltd | Professional & scientific | 2024 |
| Bowood Associates Limited | Construction | 2002 |
| Box Nation Limited | Arts & recreation | 2026 |
| Box of Porcelain Limited | Wholesale & retail | 2001 |
| Boxsafe Holdings Limited | Transport & logistics | 2025 |
| Bracken Press Limited | Professional & scientific | 1993 |
| Bradco Flooring Ltd | Construction | 2025 |
| Braddock Industries Limited | Information & communication | 2023 |
| Bradenford Software Ltd | Information & communication | 1998 |
| Brado Film Studio UK Limited | Information & communication | 2019 |
| Brain-Based Solutions Limited | Other services | 2019 |
| Bramblewood Handmade Ltd | Wholesale & retail | 2019 |
| Brambly Hedge Limited | Wholesale & retail | 1981 |
| Brandon Bespoke Limited | Manufacturing | 2023 |