| Bgluk Ltd. | Wholesale & retail | 2016 |
| BGM Motor Repairs Ltd | Wholesale & retail | 2012 |
| BGP Booze Limited | Wholesale & retail | 2022 |
| BGP Realisations PLC | Water & waste | 1938 |
| BGR Electrical Limited | Construction | 2004 |
| BH Compliance Ltd | Professional & scientific | 2017 |
| BH Construction Bramhope Ltd | Construction | 2025 |
| BH Control Services Ltd | Professional & scientific | 2026 |
| BH Energygap (Doncaster) Limited | Administrative & support | 2014 |
| BH Energygap (SSR) Limited | Administrative & support | 2025 |
| BH Energygap LLP | | 2011 |
| BH Housing Ltd | Construction | 2019 |
| BH Investment Group LLP | | 2010 |
| BH Ventures LLP | | 2011 |
| BH40 BE Happy for Nothing Ltd | Health & social care | 2023 |
| Bhabrab Ltd | Public administration | 2024 |
| Bhadal Commercial Ltd | Wholesale & retail | 2010 |
| Bhaktisoft Solutions Ltd | Information & communication | 2025 |
| Bhavana Experiences Ltd | Administrative & support | 2022 |
| Bhavik Savjani Holdings Ltd | Information & communication | 2021 |
| BHF Properties Limited | Construction | 2020 |
| BHG Consulting Limited | Professional & scientific | 2010 |
| Bhiorain Hydro Ltd | Energy | 2017 |
| Bhjt (Holdings) Limited | Financial services | 2007 |
| Bhl-Pro Ltd | Real estate | 2020 |
| BHR Health Ltd | Health & social care | 2024 |
| Bhrservices Ltd | Construction | 2025 |
| BHT Fuel Limited | Wholesale & retail | 2024 |
| BHT Land & Development Ltd | Real estate | 2026 |
| BHT Petroleum Ltd | Wholesale & retail | 2024 |
| Bhuhi Holdings Ltd | Financial services | 2025 |
| Bhupal IT Ltd | Professional & scientific | 2010 |
| BI Calculator Ltd | Construction | 2014 |
| BI Grills Ltd | Hospitality | 2019 |
| BI Technology Services Limited | Information & communication | 2019 |
| BIA Ltd | Information & communication | 2024 |
| BIA Medserv Ltd | Health & social care | 2022 |
| Biakeel Service UK Ltd | Professional & scientific | 2024 |
| Bianco Engineering Ltd | Professional & scientific | 2013 |
| Bias 2020 Limited | Financial services | 2020 |
| Biasil Construction Ltd | Construction | 2021 |
| Biatty Ltd | Real estate | 2023 |
| Biav Controls Limited | Professional & scientific | 2025 |
| Bibi Italian Ltd | Hospitality | 2024 |
| Bibi Recruitment Limited | Administrative & support | 2021 |
| Bibis Restaurants Limited | Hospitality | 1991 |
| Bibl Holdings (2015) Limited | Financial services | 2015 |
| BIC UK Facilities Management Limited | Administrative & support | 2023 |
| BIC UK North Yorkshire Limited | Construction | 2024 |
| BIC UK South Yorkshire Limited | Construction | 2024 |
| BIC UK West Yorkshire Limited | Administrative & support | 2024 |
| Bickenhall Mansions Property Limited | Real estate | 2021 |
| Bickenhall Street (BM) Limited | Real estate | 2022 |
| Bickley Insurance Services Limited | Financial services | 1993 |
| Bicom UK LLP | | 2012 |
| Bicorn Ltd | Wholesale & retail | 2017 |
| BID Couriers Ltd | Transport & logistics | 2026 |
| BID Ltd | Wholesale & retail | 2024 |
| BID Solutions Limited | Administrative & support | 2004 |
| Bidbury & Company Ltd | Wholesale & retail | 2021 |
| Bidco Oasis Limited | Professional & scientific | 2017 |
| Bidmark Limited | Professional & scientific | 2016 |
| Bidskim Ltd | Manufacturing | 2026 |
| Biedronka Store Ltd | Wholesale & retail | 2023 |
| Bielby Associates Limited | Real estate | 2009 |
| Bielby Services Ltd | Construction | 2014 |
| Bielby Transport Ltd | Extraterritorial | 2024 |
| Bienas | Professional & scientific | 2015 |
| Bierkeller Assets Ltd | Professional & scientific | 2019 |
| Bierley Bradford Limited | Health & social care | 2023 |
| Biffy Barks Ltd | Information & communication | 2018 |
| Big ASS Banners Limited | Extraterritorial | 2014 |
| Big Black Door Ltd | Professional & scientific | 2013 |
| Big Blue Whale Limited | Professional & scientific | 2015 |
| Big Box Intralogistics Ltd | Wholesale & retail | 2000 |
| Big BOY Trans Limited | Transport & logistics | 2019 |
| Big Brand Print Company Ltd | Manufacturing | 2017 |
| Big Bridge Limited | Real estate | 2002 |
| Big Bros Burgers Ltd | Hospitality | 2023 |
| Big Bros Pizza's Ltd | Hospitality | 2025 |
| Big Car Bodywork Ltd | Wholesale & retail | 2021 |
| Big City Lets Ltd | Real estate | 2013 |
| Big Cloud Limited | Real estate | 2021 |
| Big Day Dresses Ltd | Administrative & support | 2025 |
| Big Deal Cafe & Bar Limited | Hospitality | 2025 |
| Big Deal Investments Limited | Manufacturing | 2013 |
| Big Discount Ltd | Wholesale & retail | 2024 |
| Big Dreamz Ltd | Wholesale & retail | 2019 |
| Big Dude Data Ltd | Information & communication | 2025 |
| Big Face Black Cat Limited | Information & communication | 2019 |
| Big Fleet Minibus Limited | Administrative & support | 2024 |
| Big Four Happiness Limited | Hospitality | 2025 |
| Big Green Media Limited | Information & communication | 2014 |
| Big Green Software Ltd | Information & communication | 2010 |
| Big Help Project Ltd | Households | 2021 |
| Big Hitters Promotions Ltd | Arts & recreation | 2024 |
| Big Hope 4 ALL | Health & social care | 2022 |
| Big M Small C Ltd | Extraterritorial | 2016 |
| Big Mc's Container Storage Limited | Administrative & support | 2014 |
| Big Monk Construction Ltd | Construction | 2025 |