| Bettyb's Motorhome Hire Ltd | Administrative & support | 2021 |
| BEV Nipps Limited | Wholesale & retail | 2019 |
| Bevan & Bevan Limited | Financial services | 2019 |
| Beverage Innovation Limited | Wholesale & retail | 2023 |
| Beverly Investment Ltd | Real estate | 2024 |
| Beville Estate Agency Limited | Real estate | 2014 |
| Bewley Consulting Ltd | Professional & scientific | 2018 |
| Bexley Holdings Limited | Real estate | 2019 |
| Bey&O Limited | Construction | 2023 |
| Beyertec Ltd | Construction | 2020 |
| Beyinyang Ltd | Education | 2019 |
| Beyond Cloud Consulting Limited | Information & communication | 2025 |
| Beyond Gray Ltd | Administrative & support | 2014 |
| Beyond Horizons Consulting Ltd | Professional & scientific | 2023 |
| Beyond Media Design Ltd | Professional & scientific | 2025 |
| Beyond the Noise Consulting Ltd | Professional & scientific | 2026 |
| Beyond the Surface Ltd | Professional & scientific | 2024 |
| BEYOND36 (UK) Limited | Real estate | 2021 |
| BF Capital Limited | Financial services | 2024 |
| BFK Recruitment Limited | Administrative & support | 2015 |
| BFL Properties Limited | Real estate | 2025 |
| BFR Solutions Ltd | Information & communication | 2025 |
| BFS Pressroom Solutions Limited | Manufacturing | 1994 |
| BGC Transport Ltd | Transport & logistics | 2014 |
| Bhaban Limited | Hospitality | 2025 |
| Bhae Ltd | Construction | 2018 |
| Bhagat Software Services Ltd | Information & communication | 2015 |
| Bhambra Homes Ltd | Real estate | 2024 |
| Bhanu Consultancy Service Limited | Information & communication | 2017 |
| Bharatraj Limited | Professional & scientific | 2014 |
| Bhaskara Properties Limited | Real estate | 2022 |
| Bhavcom Ltd | Information & communication | 2012 |
| Bhaven Mistry Ltd | Real estate | 2019 |
| Bhbs Supplies Limited | Extraterritorial | 2021 |
| BHG Properties Services Ltd | Real estate | 2024 |
| BHM Developments and Property Management Limited | Construction | 2013 |
| BHS Bains Properties Ltd | Real estate | 2019 |
| Bhse Millars Brook Wokingham Management Company Limited | Administrative & support | 2006 |
| Bhullar Plant Hire Ltd | Administrative & support | 2025 |
| Bhumdhi KOT Travel & Trade Limited | Administrative & support | 2016 |
| Bhuni Consulting Solutions Limited | Information & communication | 2015 |
| Bhusal Properties Ltd | Real estate | 2021 |
| Bhusen Limited | Real estate | 2026 |
| Bhuva Property Group Limited | Real estate | 2024 |
| BI Consultancy Solutions Limited | Information & communication | 2013 |
| BI Data Services Ltd | Information & communication | 2022 |
| BI System Limited | Information & communication | 2011 |
| BI Tech Consulting Ltd | Information & communication | 2014 |
| Bi&M Broadcast Engineering Ltd | Information & communication | 2017 |
| Bi-Mi-Ai Ltd | Information & communication | 2022 |
| Bias Computer Consultants Limited | Real estate | 1995 |
| Biasha Ltd | Health & social care | 2020 |
| Biblical Life Ltd | Arts & recreation | 2025 |
| BID Technologies Limited | Information & communication | 2024 |
| Bidsphere Ltd | Information & communication | 2026 |
| Bidwell Consultancy Services Ltd | Information & communication | 2019 |
| Biecco Cleaning Services Ltd | Administrative & support | 2024 |
| Biecco Holdings Ltd | Financial services | 2026 |
| Biecco Laundry Services Ltd | Administrative & support | 2026 |
| Biecco Professional Carpet Cleaning Ltd | Administrative & support | 2026 |
| Biecco Professional Oven Cleaning Ltd | Administrative & support | 2026 |
| Biecco Renovations Ltd | Construction | 2025 |
| Bien-Etre Boxing Ltd | Other services | 2023 |
| Bierhaus PUB Limited | Hospitality | 2016 |
| Biffa Healthcare Solutions Ltd | Public administration | 2025 |
| Biffy Investments Ltd | Wholesale & retail | 2025 |
| Big B Entertainment Ltd | Arts & recreation | 2023 |
| Big Bark Creative Limited | Professional & scientific | 2009 |
| Big Bazaar Halal Meat Ltd | Wholesale & retail | 2023 |
| Big Bazaar Limited | Wholesale & retail | 2016 |
| Big Bazaar Online Ltd | Wholesale & retail | 2026 |
| Big Bear Digital Ltd | Information & communication | 2022 |
| Big Blue Door Limited | Information & communication | 2012 |
| Big Fish Training Limited | Professional & scientific | 2018 |
| Big Five Property Investments Limited | Real estate | 2025 |
| Big Grandma Energy Ltd | Arts & recreation | 2024 |
| Big Intelligence Ltd | Information & communication | 2012 |
| Big Sister Promotions Limited | Arts & recreation | 2002 |
| Big Sixty Limited | Households | 2023 |
| Big Thoughts in Food and Drink Limited | Administrative & support | 2013 |
| BIG3GS Ltd. | Health & social care | 2017 |
| Bigben Interactive Ltd | Manufacturing | 2009 |
| Bigchange Bidco Limited | Financial services | 2021 |
| Bigchange Midco Limited | Financial services | 2021 |
| Bigchange Topco Limited | Financial services | 2021 |
| Biggerstrongerfaster Ltd | Transport & logistics | 2016 |
| Biggins & Gallagher Formwork Limited | Construction | 2010 |
| Biggins & Gallagher Limited | Construction | 1988 |
| Biggins & Gallagher Management Limited | Professional & scientific | 2000 |
| Biggins Bros Limited | Real estate | 2007 |
| Biggins Coach House Ltd | Real estate | 2015 |
| Bigginsdavies Property Co Ltd | Real estate | 2026 |
| Biggys Diner Limited | Hospitality | 2025 |
| Bigtots Limited | Real estate | 2014 |
| Bijan's Kitchen Ltd | Hospitality | 2022 |
| Biketune Ltd | Manufacturing | 2024 |
| Bilal Bazaar Ltd | Wholesale & retail | 2025 |
| Bilal Consulting Limited | Information & communication | 2024 |
| Billadello Creatives Ltd | Information & communication | 2017 |
| Billy Roberts Properties Ltd | Real estate | 2014 |