| Blue Waters (Southbourne) Management Limited | Households | 2012 |
| Blue Wing Olive Ltd | Agriculture & fishing | 2021 |
| Bluebell Grove Limited | Real estate | 2024 |
| Bluebell Wind Farm Holding Limited | Financial services | 2017 |
| Bluebell Wind Farm Limited | Financial services | 2017 |
| Bluebells Helping Hands Limited | Health & social care | 2021 |
| Blueclovercleaning Ltd | Administrative & support | 2022 |
| Bluefins Swimming Ltd | Education | 2024 |
| Bluegas Limited | Administrative & support | 2011 |
| Bluehaze Cattery & Small Animal Hotel Limited | Other services | 2025 |
| Bluejay Strategies Ltd | Information & communication | 2025 |
| BMA Motors Ltd | Manufacturing | 2009 |
| Bodorgan Freehold Limited | Households | 2003 |
| Body Consultancy Medical Ltd | Health & social care | 2025 |
| Bolton Gelato Limited | Hospitality | 2016 |
| Boosting Business Performance Limited | Professional & scientific | 2015 |
| Boralex GP Limited | Administrative & support | 2007 |
| Boralex Limited | Construction | 2003 |
| Boralex Service Company Limited | Administrative & support | 2007 |
| Boston Artisan Holdings Ltd | Manufacturing | 2023 |
| Botanical Garden Dorset Limited | Hospitality | 2019 |
| Bothy Associates Ltd | Administrative & support | 2025 |
| Boundary Watch Limited | Administrative & support | 1997 |
| Bourne Pines Flat Management Limited | Households | 1978 |
| Bournemouth Holding Co Ltd | Hospitality | 2024 |
| Bournemouth Kart Centre Ltd | Administrative & support | 2017 |
| Bournemouth Rugby Football Club Holdings Ltd | Financial services | 2025 |
| Bowfin Limited | Construction | 2010 |
| Bowraven Limited | Information & communication | 1990 |
| Brads Rads & Boilers Ltd | Construction | 2021 |
| Bramble Pubs Limited | Financial services | 2023 |
| Brayan 23 Ltd | Administrative & support | 2023 |
| Bretan Ltd | Construction | 2024 |
| Brickhouse Lane Company Limited | Real estate | 1997 |
| Brickmere Limited | Real estate | 2021 |
| Bright Solar Lighting Ltd | Wholesale & retail | 2022 |
| Brightwater Commercial Ltd | Real estate | 2025 |
| Britannia London Limited | Manufacturing | 2016 |
| Broad Reach Estates Limited | Construction | 2001 |
| Broadleaf Management Services Limited | Real estate | 1990 |
| Broadshard Limited | Households | 2008 |
| Broadway Events Limited | Administrative & support | 2009 |
| Brodtec Ltd | Construction | 2019 |
| Brogan Tate Limited | Information & communication | 2025 |
| Brolinz Limited | Administrative & support | 2015 |
| Brookland Court (Ferndown) Limited | Real estate | 2010 |
| Brooklyn Blue Limited | Construction | 2021 |
| Brooks Investments Ltd | Real estate | 2026 |
| Bryant and Trowbridge Limited | Construction | 1999 |
| Budbros Ltd | Wholesale & retail | 2022 |
| Bugler Transport Ltd | Transport & logistics | 2012 |
| Build Reliance Limited | Construction | 2013 |
| Build South Ltd | Construction | 2026 |
| Burgess Hodgson Audit 2025 Limited | Professional & scientific | 1997 |
| Burgess Hodgson Services Limited | Professional & scientific | 2015 |
| Burnett Technical Ltd | Administrative & support | 2009 |
| Burns Property Consultants Limited | Real estate | 2008 |
| Burton (MAN) OFF Licence Ltd | Wholesale & retail | 2018 |
| Burton Day Nursery Limited | Education | 2004 |
| Burwood Investments Limited | Professional & scientific | 2011 |
| Byout Salon Ltd | Other services | 2019 |
| Byroc Play Productions Limited | Administrative & support | 1976 |
| C Donnison Ltd | Administrative & support | 2025 |
| C Gordon Associates Limited | Health & social care | 2019 |
| C L Burke Limited | Arts & recreation | 2012 |
| C Swatton Planning Services Ltd | Professional & scientific | 2024 |
| C V Down Limited | Construction | 1987 |
| C&H Scaffolding Ltd | Construction | 2020 |
| C. Q. Chandlers Limited | Other services | 1973 |
| C.B.K. Properties Limited | Real estate | 1999 |
| C.M. (Builders Properties) Limited | Construction | 1971 |
| C.M.A. (Nemesis) Limited | Other services | 1992 |
| CAB Social Limited | Information & communication | 2025 |
| Cad-Created Ltd | Professional & scientific | 2020 |
| Cadel Consulting Limited | Professional & scientific | 2017 |
| Caernarvon House Freehold Limited | Real estate | 2013 |
| Café Nucleus Collection Limited | Hospitality | 2014 |
| Calceus Trading Co Ltd | Wholesale & retail | 2016 |
| Caldwell Group Limited | Professional & scientific | 2008 |
| Call a Car Ringwood Ltd | Transport & logistics | 2024 |
| Calleva Arms Ltd | Hospitality | 2021 |
| Calmore Machinery Company Limited | Manufacturing | 1973 |
| Campanile South Ltd | Hospitality | 2023 |
| Camps International (UK) Limited | Professional & scientific | 2006 |
| Camps International Group Limited | Administrative & support | 2002 |
| Candlesticks Property LLP | | 2016 |
| Canfield Healthcare Consulting LP | | 2019 |
| Canned Soup Ltd | Arts & recreation | 2016 |
| Cantech Solutions Ltd. | Manufacturing | 2003 |
| Capital Living Investments Ltd | Professional & scientific | 2021 |
| Capital Venture Limited | Other services | 1993 |
| Caradoc Management Ltd | Real estate | 2021 |
| Carbon Miles Ltd | Wholesale & retail | 2024 |
| Cardbooks Ltd | Information & communication | 2026 |
| Careline Support Limited | Other services | 2019 |
| Carolan Consultants Ltd | Professional & scientific | 2023 |
| Carole Tonkiss Properties Limited | Financial services | 2015 |
| Carpenter Environmental Limited | Professional & scientific | 2024 |
| Cars Hotspot Limited | Wholesale & retail | 2015 |
| Carter's Quay Estate Management Company Limited | Households | 2014 |