| BUC Prestatyn Limited | Health & social care | 2022 |
| BUC Property Investment Limited | Real estate | 2024 |
| BUC Wakefield Limited | Health & social care | 2022 |
| Buchanan Logistics Services Ltd | Transport & logistics | 2026 |
| Buchiya Properties Ltd | Real estate | 2026 |
| Buckenham Clinical Services Limited | Health & social care | 2022 |
| Buckley Acquisitions Limited | Financial services | 2022 |
| Buckley Specialist Recruitment Limited | Administrative & support | 2016 |
| Buckleys Property Services Ltd | Construction | 2023 |
| Buckshaw Property Ltd | Real estate | 2015 |
| Buckshee Productions Limited | Arts & recreation | 2007 |
| Budapest Food Store Limited | Wholesale & retail | 2019 |
| Budget Blinds Limited | Manufacturing | 2001 |
| Budget Hire Ltd | Administrative & support | 2021 |
| BUFFALO7 Limited | Professional & scientific | 2010 |
| BUG Minus Ltd | Information & communication | 2025 |
| Buga Limited | Hospitality | 2019 |
| Buggaz Ltd | Wholesale & retail | 2021 |
| Buhlebenkosi Limited | Health & social care | 2014 |
| Build Developments Ltd | Construction | 2014 |
| Build FIX Design Bolton Ltd | Construction | 2025 |
| Build Northwest Projects Ltd | Construction | 2024 |
| Build Property Services Limited | Construction | 2020 |
| Build Renovate Create Ltd | Construction | 2025 |
| Build UP Coaching & Consulting Limited | Administrative & support | 2024 |
| Builda Ltd | Administrative & support | 2021 |
| Building Bespoke Construction Ltd | Construction | 2023 |
| Building Construction 125 Limited | Construction | 2025 |
| Building Efficient Life Through Learning and Support (Bells) Initiative | Information & communication | 2025 |
| Building Materials Solution Limited | Wholesale & retail | 2024 |
| Buildology (NW) Limited | Construction | 2018 |
| Buildpave Holdings Ltd | Financial services | 2021 |
| Buildpave Limited | Wholesale & retail | 2017 |
| Buildsworth Construction Limited | Construction | 2018 |
| Buildsworth Constructions NW Ltd | Construction | 2022 |
| Buildyourbranduk Ltd | Professional & scientific | 2025 |
| Built by Howie Ltd | Information & communication | 2017 |
| Built Different Talent Limited | Administrative & support | 2026 |
| Built From Nothing Ltd | Professional & scientific | 2026 |
| Buita Cleaning Services Ltd | Administrative & support | 2022 |
| Bukharians Ltd | Wholesale & retail | 2024 |
| Bukittinggi Limited | Hospitality | 2021 |
| Buksh Capital Ltd | Hospitality | 2025 |
| BUL Trade Ltd | Wholesale & retail | 2010 |
| Bull & Partners Ltd | Real estate | 2025 |
| Bulldog Construction Ltd | Construction | 2024 |
| Bulldog Logistics Ltd | Transport & logistics | 2022 |
| Bulldog Property Assets Ltd | Real estate | 2026 |
| Bulldog Property Ltd | Real estate | 2023 |
| Bullen Conservation Limited | Construction | 2003 |
| Bumble 2020 Ltd | Extraterritorial | 2020 |
| Bundle and Bliss Limited | Wholesale & retail | 2019 |
| Buoey Electrical Services & Testing Limited | Construction | 2026 |
| Burank Top Clean Limited | Administrative & support | 2025 |
| Burdbox Limited | Administrative & support | 2015 |
| Bureau #2 Limited | Construction | 2016 |
| Bureau Management Strategies Ltd | Other services | 2023 |
| Burger Deal Limited | Hospitality | 2026 |
| Burger Express Farnworth Ltd | Hospitality | 2024 |
| Burger Joint (NW) Ltd | Hospitality | 2025 |
| Burgero Ltd | Hospitality | 2024 |
| Burgers O Clock Ltd | Hospitality | 2026 |
| Burgers to Love Limited | Hospitality | 2021 |
| Burgess & Gilbert Group Ltd | Wholesale & retail | 2021 |
| Burleigh Properties Limited | Professional & scientific | 1979 |
| Burleigh Stone Limited | Construction | 2008 |
| Burnett Service Centre Ltd | Wholesale & retail | 2010 |
| Burneys Limited | Extraterritorial | 1933 |
| Burni Ltd | Wholesale & retail | 2023 |
| Burns Group Holdings Limited | Wholesale & retail | 2022 |
| Burnthwaite Hall Management Company Limited | Professional & scientific | 2018 |
| Burraq Trading UK Limited | Wholesale & retail | 2024 |
| Burrow Education Ltd | Education | 2014 |
| Burrow Lodging Ltd | Hospitality | 2024 |
| Bursco Limited | Professional & scientific | 2022 |
| Burt Wesley & Sons Limited | Wholesale & retail | 2014 |
| Burtenshaw Technology Limited | Information & communication | 2026 |
| Burton James Estate Agents Limited | Real estate | 2021 |
| Burton James Financial Services Limited | Financial services | 2026 |
| Bury 80 Limited | Hospitality | 2025 |
| Bury Commerce Ltd | Wholesale & retail | 2025 |
| Bury Haulage Ltd | Wholesale & retail | 2017 |
| Bury Limited | Construction | 2024 |
| Bury Road Trading Ltd | Wholesale & retail | 2019 |
| Bury Times Limited | Wholesale & retail | 2023 |
| Bury Times Zone Limited | Wholesale & retail | 2026 |
| Bury Trading Ltd | Wholesale & retail | 2024 |
| BUS Electrical Limited | Wholesale & retail | 2011 |
| Busal Limited | Wholesale & retail | 2024 |
| Business & Architecture Ltd | Professional & scientific | 2024 |
| Business Energy Group Ltd | Wholesale & retail | 2024 |
| Business Financing Solutions Limited | Financial services | 2007 |
| Business Insurance Broking Services Limited | Administrative & support | 2008 |
| Business Remedy Limited | Administrative & support | 2022 |
| Business Solutions Bolton Limited | Real estate | 2021 |
| Business Spectrum Limited | Professional & scientific | 2010 |
| Business Systematic Limited | Administrative & support | 2023 |
| Business Systems and Design Management Limited | Administrative & support | 2014 |
| Business Transformation Advisory and Delivery Limited | Information & communication | 2026 |
| Busmere Holdings Ltd | Financial services | 2025 |