| Bestrad Limited | Health & social care | 2013 |
| Besty Foods Ltd | Wholesale & retail | 2022 |
| Beta Complete Services Ltd | Construction | 2019 |
| Beta Polymers Ltd | Wholesale & retail | 2021 |
| Betah Ltd | Wholesale & retail | 2026 |
| Beth Best Property Group Limited | Real estate | 2026 |
| Bethsaida Care Limited | Health & social care | 2018 |
| Betomis Limited | Information & communication | 2015 |
| Better Business Consultancy Vibe Ltd | Professional & scientific | 2021 |
| Better Oasis Limited | Health & social care | 2020 |
| Better World Solutions Ltd | Construction | 2021 |
| Bettermorphosis Journeys Limited | Other services | 2013 |
| Betterpace Limited | Financial services | 1996 |
| Betts Homes Ltd | Extraterritorial | 2025 |
| Betts Property Holdings Limited | Real estate | 2016 |
| Betts Real Estate Ltd | Real estate | 2022 |
| Betts Scaffolding Limited | Construction | 2021 |
| Betty Rose Developments Ltd | Construction | 2013 |
| Beulah House Properties Ltd | Real estate | 2021 |
| BEV Cushion Limited | Professional & scientific | 2006 |
| Beverley Care Homes Ltd | Health & social care | 2025 |
| Beverley Hampshire Airworthiness Support Ltd | Professional & scientific | 2012 |
| Beverley Knights Limited | Other services | 2024 |
| Bevero Ltd | Wholesale & retail | 2017 |
| BEW Trading Limited | Wholesale & retail | 2024 |
| Bewell Media Ltd | Information & communication | 2023 |
| Bewilderwood Limited | Professional & scientific | 2007 |
| Bexford Education Ltd | Education | 2026 |
| Bexleyheath Restaurants Ltd | Hospitality | 2022 |
| Bexwell Tractors Limited | Real estate | 1971 |
| Beyond 147 Limited | Wholesale & retail | 2021 |
| Beyond 2030 Ltd. | Professional & scientific | 2012 |
| Beyond ANY Limits Franchise Ltd | Financial services | 2025 |
| Beyond Barber Ltd | Other services | 2022 |
| Beyond Boundaries Academy & H. UK Ltd | Health & social care | 2020 |
| Beyond Limits Gyms Ltd | Arts & recreation | 2019 |
| Beyond Medispa Services Limited | Wholesale & retail | 2017 |
| Beyondcuriosity Limited | Administrative & support | 2000 |
| Beyourbrave Ltd | Education | 2023 |
| Bezakk Group Ltd | Construction | 2015 |
| BF Investments Limited | Real estate | 2024 |
| Bfoods (U.K.) Limited | Wholesale & retail | 2017 |
| BG Homes (Norfolk) Ltd | Construction | 2024 |
| BGB Lettings and Property Management Ltd | Real estate | 2023 |
| BGD Consulting (UK) Limited | Professional & scientific | 2007 |
| Bgel Ltd | Wholesale & retail | 2019 |
| BGG Advice Centre Ltd | Financial services | 2025 |
| BGH Consultants Limited | Professional & scientific | 2012 |
| Bglamd Ltd | Other services | 2019 |
| BGM Estimating & Surveying Services Ltd | Professional & scientific | 2013 |
| BGM Norfolk Limited | Water & waste | 2024 |
| Bguk Ltd | Wholesale & retail | 2012 |
| BGX Petroleum Company Ltd | Mining & quarrying | 2019 |
| BH 2020 Limited | Real estate | 2019 |
| BH Carpentry Ltd | Construction | 2024 |
| BH Drayton 2020 Ltd | Health & social care | 2019 |
| BH Innovation Consultant Ltd | Real estate | 2021 |
| BH Logistic & Delivery Ltd | Transport & logistics | 2026 |
| BH Studio Ltd | Other services | 2016 |
| BH Trees and Woodland Consultancy Ltd | Administrative & support | 2016 |
| Bhai Investment Group Ltd | Financial services | 2023 |
| Bhaijaans Restaurants Limited | Hospitality | 2016 |
| Bham Capital Limited | Financial services | 2019 |
| Bhawanis Incorporate Limited | Real estate | 2024 |
| BHD (British Home Design) Ltd | Professional & scientific | 2021 |
| Bhhm Employer Limited | Financial services | 2025 |
| BHP Solar Limited | Professional & scientific | 2014 |
| Bhpp Limited | Real estate | 2004 |
| Bhse Centennial Park Elstree Management Company Limited | Real estate | 2007 |
| Bhse Pastures Winnersh Management Company Limited | Administrative & support | 2006 |
| Bhte Ltd | Information & communication | 2025 |
| Biako Ltd | Information & communication | 2025 |
| Biccotest Limited | Manufacturing | 2002 |
| Bickerston Farm Limited | Agriculture & fishing | 1999 |
| Bicol UK Healthcare Services Ltd | Health & social care | 2015 |
| Bicotest Limited | Manufacturing | 2008 |
| Bicycle Links CIC | Water & waste | 2011 |
| Biddy's Tea Room Limited | Wholesale & retail | 2023 |
| Bide-A-Wee Ltd | Real estate | 2020 |
| Bidwell Holdings Limited | Real estate | 2020 |
| Bienvenue (Norfolk) Limited | Hospitality | 2009 |
| Biercafe Norwich Limited | Wholesale & retail | 2018 |
| Biffcam Ltd | Information & communication | 2003 |
| Big 6 Compliance Limited | Construction | 2023 |
| Big Andy's Gym Ltd | Arts & recreation | 2016 |
| Big Blue Consulting Ltd | Professional & scientific | 2024 |
| Big BOY Solutions Ltd | Professional & scientific | 2022 |
| Big Dog Renovations Limited | Real estate | 2023 |
| Big Green PIG Limited | Real estate | 2017 |
| Big Kids Bounce Ltd | Arts & recreation | 2023 |
| Big MAN 1 Ltd | Administrative & support | 2019 |
| Big MAX Limited | Hospitality | 2017 |
| Big Micky's Food Mart Ltd | Hospitality | 2024 |
| Big Pixel Community CIC | Information & communication | 2026 |
| Big Pixel Consulting Ltd | Information & communication | 2024 |
| Big Red Wheel (BRW) Clinical Services Limited | Health & social care | 2019 |
| Big SAJ Edward Road Ltd | Hospitality | 2022 |
| Big SAJ Original Limited | Hospitality | 2018 |
| Big SAJ Sparkhill Limited | Hospitality | 2021 |
| Big Sky Additions Limited | Administrative & support | 2010 |