| BAA Creative Limited | Information & communication | 2015 |
| Badcock Properties Ltd | Construction | 2021 |
| Baitpax Limited | Manufacturing | 2023 |
| Bankmile Limited | Extraterritorial | 1950 |
| Barbara Mawer Enterprises Limited | Manufacturing | 2021 |
| Barber Quma Ltd | Other services | 2021 |
| Barnacott Limited | Real estate | 2020 |
| Barnard Research Limited | Administrative & support | 2008 |
| Barnes Builders Ltd | Construction | 2012 |
| Bartlett Cooke Group Limited | Professional & scientific | 2012 |
| Barton Mews Management Company Limited | Extraterritorial | 2011 |
| Bay Breaks Ltd | Hospitality | 2021 |
| Bay Trade Limited | Construction | 2025 |
| Beach House Collection Limited | Real estate | 2018 |
| Beach One Limited | Hospitality | 2014 |
| Beauty With Sierra Ltd | Other services | 2024 |
| Beecollectibles Limited | Wholesale & retail | 2026 |
| Believe Academy Performing Arts C.I.C. | Arts & recreation | 2016 |
| BEN Rodwell Ltd | Construction | 2025 |
| Benoni Holdings Limited | Financial services | 2023 |
| Benoni Nursing Home Limited | Health & social care | 2003 |
| Berry Carpentry and Building Limited | Construction | 2015 |
| Bestec (UK) Limited | Professional & scientific | 2012 |
| BILLY4SHOES Limited | Hospitality | 2014 |
| BL Catharine Street Ltd | Real estate | 2021 |
| Black Sand Industries Limited | Wholesale & retail | 2022 |
| Blackboards Europe Limited | Manufacturing | 2011 |
| Bloom Remedies Ltd | Manufacturing | 2018 |
| Blooming Battlefields CIC | Professional & scientific | 2025 |
| BLP Consulting Limited | Professional & scientific | 2021 |
| Blue Dolphin Leisure Limited | Transport & logistics | 2001 |
| Blue Door Penzance Ltd | Wholesale & retail | 2026 |
| Bluefurball Ltd | Wholesale & retail | 2017 |
| Bocka DU Ltd | Information & communication | 2026 |
| Bollowal Developments Ltd | Construction | 2013 |
| Bombay Cuisine Limited | Hospitality | 2018 |
| Bombus Holdings Limited | Hospitality | 2018 |
| Bookkeeping Solutions(Sw) Ltd. | Professional & scientific | 2019 |
| BOS Verbas Holidays Ltd | Hospitality | 2018 |
| Boscarnek Health Ltd | Health & social care | 2017 |
| Boscaswell Gardens Management Association Ltd | Other services | 2017 |
| Bosena Ltd | Information & communication | 2019 |
| Bosleven Management Limited | Households | 1989 |
| Boston Manor Road Residents Limited | Households | 1996 |
| Bostraze Plant Limited | Administrative & support | 2021 |
| Bostraze Recycling Limited | Water & waste | 2018 |
| Bosuns Property Ltd | Construction | 2025 |
| Bosvenning Homes Ltd | Construction | 2026 |
| Bosworth Roofing Limited | Construction | 1998 |
| Botrea Limited | Construction | 2004 |
| Braddon Building & Roofing Limited | Construction | 2021 |
| Brand POP Ltd | Professional & scientific | 2025 |
| Brea Vean Limited | Hospitality | 2019 |
| Breakthrough Books Collective Limited | Information & communication | 2023 |
| Bremner Mckenna Associates Ltd | Professional & scientific | 2009 |
| Brempark Limited | Real estate | 2000 |
| Breon O'Casey Limited | Wholesale & retail | 2007 |
| British Cured Pilchards Limited | Manufacturing | 1981 |
| BRM Property Limited | Construction | 2002 |
| Broadarrow Trading Limited | Wholesale & retail | 2025 |
| Brooks & Bright Carpentry Limited | Construction | 2024 |
| Brooks Property Investments Limited | Real estate | 2015 |
| Bryncliffe Limited | Real estate | 2022 |
| Buckle and Band Ltd | Wholesale & retail | 2021 |
| Budding Nature C.I.C. | Education | 2022 |
| Buddle Villas Ltd | Real estate | 2025 |
| Build 1-2-3 Limited | Construction | 2022 |
| Build IT Cornwall Ltd | Construction | 2020 |
| Buildbooks Cornwall Ltd | Professional & scientific | 2026 |
| Bunyip Services Limited | Health & social care | 2021 |
| Burgan Management Company Limited | Real estate | 2020 |
| Burroughs & Kearey (Funeral Directors) Limited | Other services | 2006 |
| Burroughs Construction Limited | Construction | 2013 |
| Buttons and Pebbles Ltd | Professional & scientific | 2021 |
| C & O Reeves Limited | Extraterritorial | 2013 |
| C R Residential Lettings Ltd | Real estate | 2007 |
| C&Itc Limited | Information & communication | 2015 |
| C&S Crosbie Ltd | Agriculture & fishing | 2021 |
| C-Volution Limited | Professional & scientific | 2022 |
| Cadieux Rule Properties Limited | Households | 2021 |
| Camlet Properties Limited | Real estate | 2013 |
| Campharm Limited | Professional & scientific | 2005 |
| Cape Cornwall Carpentry Ltd | Manufacturing | 2026 |
| Cape Cornwall Club Ltd | Hospitality | 2019 |
| Cape Cornwall Group Ltd | Financial services | 2026 |
| Cape Star Food Limited | Hospitality | 2025 |
| Cape Trelew RTM Company Limited | Households | 2013 |
| Captain Jack Holdings Limited | Financial services | 2025 |
| Car Valeting and Detailing Ltd | Administrative & support | 2021 |
| Carbon Sense Ltd | Professional & scientific | 2022 |
| Card Cloud Ltd | Wholesale & retail | 2022 |
| Cares 2 Care Ltd | Administrative & support | 2022 |
| Carn Brea Outdoor Catering Ltd | Hospitality | 2025 |
| Carn Gowla Medical Limited | Health & social care | 2018 |
| Carn Grean Ltd | Hospitality | 2025 |
| Carn Metals Limited | Manufacturing | 1987 |
| Carn Solutions Limited | Professional & scientific | 2015 |
| Carnaby Cross Limited | Administrative & support | 2016 |
| Carnon EAR Care Limited | Health & social care | 2023 |
| Carole Court (Camborne) Management Company Limited | Households | 2019 |