| Bingham Properties Limited | Hospitality | 1992 |
| Binz Cleaned Ltd | Administrative & support | 2025 |
| Birrell Homes Ltd | Real estate | 2023 |
| Birrell Properties Limited | Real estate | 2022 |
| Birrell Risks & Co Ltd | Financial services | 2026 |
| Bisarya Ltd | Health & social care | 2017 |
| Bitteswell Commercial Services Ltd | Professional & scientific | 2019 |
| Bitteswell Construction Limited | Construction | 2002 |
| Bitteswell Parva Drainage Company Limited | Water & waste | 2011 |
| Bklc Property Rentals Limited | Real estate | 2015 |
| Blackdown Motor Company Limited | Wholesale & retail | 2003 |
| Blackthorn Management Services Limited | Professional & scientific | 2015 |
| Blend Coffee and Cakes Limited | Hospitality | 2018 |
| Bliss and Beauty Ltd | Other services | 2014 |
| Bloch Ltd | Health & social care | 2017 |
| Blousey Browne Limited | Extraterritorial | 2011 |
| Blue Bear Transport Ltd | Transport & logistics | 2020 |
| Blue Circle (HS) Limited | Professional & scientific | 1960 |
| Blue Circle (RCM) Limited | Professional & scientific | 1948 |
| Bluebird Distributors Limited | Transport & logistics | 1978 |
| Bluefield Consultants Limited | Professional & scientific | 2017 |
| Bluefield Farm Enterprise Limited | Professional & scientific | 2012 |
| Blueprint Consultancy 2022 Limited | Professional & scientific | 2022 |
| Blueprint Solutions Limited | Professional & scientific | 2016 |
| Blueprnt Limited | Professional & scientific | 2024 |
| Blueskyblue UK Limited | Other services | 2010 |
| Blythe Property Shop Ltd | Real estate | 2019 |
| Blythin & Brown (Corporate Solutions) Ltd | Financial services | 2018 |
| BMS 2023 Limited | Professional & scientific | 2023 |
| BMS Controls and Energy Limited | Construction | 2015 |
| Bobstay Limited | Professional & scientific | 2010 |
| BON VIE Limited | Professional & scientific | 2007 |
| BONSAI2U Ltd. | Wholesale & retail | 2017 |
| Bootroom Brands Limited | Wholesale & retail | 2025 |
| Bosworth Boiler Tech Ltd | Other services | 2011 |
| Bowden Management Company Limited | Real estate | 2005 |
| Boyde Marine Ltd | Professional & scientific | 2024 |
| Bozel Investments Ltd | Real estate | 2026 |
| BPS Innovative Media Ltd. | Manufacturing | 1994 |
| Bradshaw Asset Holding Ltd | Households | 2022 |
| Bramley Motor Works Ltd | Wholesale & retail | 2011 |
| Brandsma Medical Ltd | Education | 2020 |
| Breathe Easy Gardens Ltd | Administrative & support | 2025 |
| Brier Properties Limited | Real estate | 2000 |
| Bright Private Limited | Health & social care | 2022 |
| Brinkleys Restaurant Services Limited | Other services | 1985 |
| Britannia Data Management Limited | Financial services | 1981 |
| Britannia Equity UK Ltd | Real estate | 2016 |
| British Association for Counselling and Psychotherapy | Health & social care | 1987 |
| BRL Partners Limited | Financial services | 2026 |
| Broadleaf Consult Ltd | Professional & scientific | 2023 |
| Broadway Health (Leicester) Ltd | Health & social care | 2023 |
| Bronze World Property Ltd | Real estate | 2023 |
| Bronzed Angel Limited | Other services | 2012 |
| Brookfleet Properties Ltd | Real estate | 2021 |
| Broome & Associates Limited | Construction | 2013 |
| Broomfields Legal Services Limited | Extraterritorial | 2015 |
| Broomfields Solicitors LLP | | 2009 |
| Broughton Astley Skip Hire Ltd | Water & waste | 2010 |
| Browns Health and Fire Safety Ltd | Other services | 2024 |
| Bryn Dinas Glamping Pods Ltd | Hospitality | 2022 |
| BSG Enterprises Ltd | Real estate | 2021 |
| Buildfront Construction Limited | Construction | 2021 |
| Building & Maintenance Services (Holdings) Limited | Professional & scientific | 2014 |
| Building & Maintenance Services Property Limited | Real estate | 2014 |
| Built Environments Limited | Construction | 2017 |
| Burgess Plumbing & Heating Ltd | Construction | 2019 |
| Burning Woman Ltd | Arts & recreation | 2021 |
| Bursty Ltd | Information & communication | 2021 |
| Burton Bike Bits Limited | Wholesale & retail | 2011 |
| Burton Joinery & Project Management Ltd | Construction | 2023 |
| Business Energy Consultants Limited | Professional & scientific | 2012 |
| Busy Bees Florist Ltd | Wholesale & retail | 2019 |
| BV Property Limited | Financial services | 2016 |
| BW Atkinson Holdings Limited | Financial services | 2018 |
| BWA Estates Ltd | Hospitality | 2018 |
| Byapp Consultancy Ltd | Information & communication | 2016 |
| Bylaurabent Ltd | Professional & scientific | 2026 |
| C & T Pradhans Limited | Other services | 2011 |
| C & W Partners Limited | Construction | 1994 |
| C and C Leire Holdings Limited | Financial services | 2021 |
| C and C Leire Limited | Hospitality | 2018 |
| C Begley Building Limited | Construction | 2005 |
| C E Moss Limited | Other services | 2010 |
| C Gurkha Curry Limited | Hospitality | 2026 |
| C K Cars Midlands Chauffeurs Limited | Transport & logistics | 2023 |
| C V Commercials (UK) Limited | Other services | 2009 |
| C W Marketing Limited | Wholesale & retail | 1992 |
| C&N Sealants Limited | Construction | 2005 |
| C. Green Planning Limited | Professional & scientific | 2023 |
| C. S. W. Properties Limited | Construction | 1977 |
| C.D.A. Mann Ltd | Health & social care | 2021 |
| C.Esler Consulting Limited | Other services | 2010 |
| C.K.S. Precision Ltd. | Manufacturing | 1986 |
| C.N.S.(2023) Ltd | Professional & scientific | 2023 |
| C.S. Construction Holdings Limited | Financial services | 2017 |
| C.U. Jimi Consultancies Limited | Administrative & support | 2004 |
| C3D Realisations Limited | Professional & scientific | 2014 |
| Cabtop Ltd | Wholesale & retail | 2025 |
| Cadal Craft Ltd | Manufacturing | 2020 |