| Big Mountain Consultancy Limited | Information & communication | 2018 |
| Big P Properties Management Ltd | Real estate | 2022 |
| Big Papa Fastfood Ltd | Hospitality | 2023 |
| Big Phillies Ltd | Wholesale & retail | 2022 |
| Big Picture Properties Ltd | Real estate | 2020 |
| Big Pink Studio Limited | Extraterritorial | 2012 |
| Big Speed Trans Ltd | Transport & logistics | 2019 |
| Big Steps Limited | Health & social care | 2013 |
| Big Talk Mars Ltd | Information & communication | 2026 |
| Big TED Promotions Limited | Arts & recreation | 2021 |
| Big Wash Kirkstall Ltd | Administrative & support | 2024 |
| Big Waste Services Limited | Professional & scientific | 2006 |
| Bigchange Group Limited | Information & communication | 2011 |
| Bigchange Limited | Information & communication | 2012 |
| Bigfarm Foods UK Limited | Wholesale & retail | 2024 |
| Bigga Boys Ltd | Hospitality | 2025 |
| Biggin Investments Limited | Administrative & support | 2020 |
| Bighead Creative Ltd | Professional & scientific | 2010 |
| Bignall Property LLP | | 2023 |
| Bignumberten Enterprises Ltd | Financial services | 2025 |
| Bigselle Limited | Transport & logistics | 2025 |
| Bigzbarber Ltd | Other services | 2025 |
| Bijoux Lifestyle Ltd | Wholesale & retail | 2025 |
| Bijunet Ltd | Wholesale & retail | 2021 |
| Bike and Boot Inns Limited | Hospitality | 2015 |
| Bike Booster Limited | Manufacturing | 2025 |
| Bikleen Limited | Hospitality | 2020 |
| Bilachao Ltd | Wholesale & retail | 2025 |
| Bilal Legends Trading Co Ltd | Hospitality | 2023 |
| Bilals Diner Ltd | Hospitality | 2025 |
| Bilauda Limited | Health & social care | 2022 |
| Bilidan Property Investment Ltd | Real estate | 2025 |
| Bilkhu Properties (Yorkshire) Ltd | Real estate | 2017 |
| Bill Investigators Ltd | Administrative & support | 2017 |
| Bill Minder Limited | Other services | 2023 |
| Billakpe & Co Limited | Information & communication | 2019 |
| Billam (Sheffield) Realisations Limited | Energy | 1953 |
| Billions 1BA Ltd | Wholesale & retail | 2025 |
| Billions Lounge Leeds Ltd | Hospitality | 2018 |
| Billions Vapes Ltd | Wholesale & retail | 2022 |
| Billman Leeds Ltd | Construction | 2025 |
| Bills and Beats Ltd | Information & communication | 2024 |
| Bills Inc Ltd | Real estate | 2016 |
| Billy Grey Holdings Limited | Financial services | 2026 |
| Billy Whizz Removals Limited | Transport & logistics | 2024 |
| Billyhughes&Co. Limited | Professional & scientific | 2007 |
| Billy’S BUS Ltd | Other services | 2025 |
| Bilsdale Properties Limited | Real estate | 1994 |
| Biltom Ltd | Hospitality | 2017 |
| Biltt Scaffolding Ltd | Construction | 2023 |
| Bimmell Limited | Extraterritorial | 2022 |
| BIN Karamat Properties Ltd | Real estate | 2024 |
| Bin-Nadeem Ltd | Health & social care | 2021 |
| Binary Class Products Ltd | Wholesale & retail | 2024 |
| Bindethics Ltd | Manufacturing | 2021 |
| Bindi Consulting Services Ltd | Professional & scientific | 2014 |
| Bindoff Media Ltd | Information & communication | 2009 |
| Bingley UK Developments Limited | Real estate | 2020 |
| Bingley Wingfield Care Limited | Health & social care | 2013 |
| Bingo Supplies Limited | Wholesale & retail | 2012 |
| Binioptical Ltd | Health & social care | 2023 |
| Binna's Touch Limited | Health & social care | 2020 |
| Binnie Goods Ltd | Wholesale & retail | 2022 |
| Binns Ltd | Information & communication | 2018 |
| Binsun Ltd | Wholesale & retail | 2024 |
| Binwei Study Limited | Education | 2025 |
| Binyam Service Ltd | Manufacturing | 2018 |
| BIO Hazard & Specialist Cleaning Solutions Ltd | Administrative & support | 2024 |
| BIO Solutions Group Ltd | Financial services | 2021 |
| BIO Waste OIL Ltd | Water & waste | 2022 |
| Bio-Sci Enterprise Limited | Health & social care | 2016 |
| BIO2PURE Limited | Water & waste | 2019 |
| Bioanalytiq Ltd | Information & communication | 2026 |
| Biochem Health Supplements Ltd | Wholesale & retail | 2025 |
| Biodolf Limited | Health & social care | 2021 |
| Biogreen Energy Solutions Ltd | Construction | 2017 |
| Biogreen Plumbing & Heating Ltd | Construction | 2018 |
| Biogreen Solutions Group of Companies Ltd | Construction | 2017 |
| Biogreen Solutions Ltd | Construction | 2011 |
| Biomed Healing Ltd | Other services | 2015 |
| Biometan (UK) 1 Ltd | Energy | 2024 |
| Biometan (UK) 2 Ltd | Energy | 2025 |
| Biometan (UK) 3 Ltd | Energy | 2026 |
| Biometan (UK) 4 Ltd | Energy | 2026 |
| Biometan (UK) 5 Ltd | Energy | 2026 |
| Bionavix Limited | Professional & scientific | 2025 |
| Biophilic Living Limited | Professional & scientific | 2021 |
| Biorene Ltd | Administrative & support | 2021 |
| Bioresonance Limited | Health & social care | 2018 |
| Bioresq Skincare Limited | Wholesale & retail | 2020 |
| Bioshield Limited | Administrative & support | 2010 |
| Biostraw Ltd | Manufacturing | 2018 |
| BIR Graphics Engineering Limited | Professional & scientific | 2024 |
| BIR TUN Limited | Wholesale & retail | 2025 |
| Birchall Projects Limited | Construction | 2025 |
| Birchroyd Joinery Ltd | Construction | 2023 |
| Birchwood Decorators Limited | Construction | 2022 |
| Birchwood Mews Management Co. Limited | Households | 1983 |
| Birchwood Point Maintenance Company Limited | Real estate | 1996 |
| Bird Accounting Ltd | Professional & scientific | 2025 |