| Brush & Beyond Artistry Limited | Manufacturing | 2025 |
| Brush Buggy Limited | Wholesale & retail | 2020 |
| Brxh Limited | Hospitality | 2023 |
| Bryan Pollard Scenic Carpentry Ltd | Construction | 2014 |
| Bryn Daniel Hair Company Limited | Other services | 2003 |
| BS Autos & Bodywork Ltd | Wholesale & retail | 2024 |
| BS Tech Solutions Ltd | Information & communication | 2021 |
| BSA Manchester Ltd | Professional & scientific | 2025 |
| BSK Landscapes Limited | Administrative & support | 2016 |
| BSK Properties Ltd | Households | 2017 |
| BSN Builders Limited | Construction | 2021 |
| Bssr Investments Limited | Real estate | 2021 |
| BT Family Ltd | Real estate | 2025 |
| BT Signatures Ltd | Real estate | 2023 |
| Btcom Ltd. | Administrative & support | 2011 |
| BTD Fire Protection Limited | Professional & scientific | 2020 |
| BTE Consults Ltd | Wholesale & retail | 2025 |
| BTG Freight Limited | Wholesale & retail | 2023 |
| BTK Enterprises Ltd | Financial services | 2023 |
| BTY Ltd | Extraterritorial | 2025 |
| Buana Ltd | Hospitality | 2023 |
| Bubble Bar AJ Ltd | Hospitality | 2019 |
| Bubble O Tea Bar Ltd | Hospitality | 2024 |
| Bubble Valeting Ltd | Administrative & support | 2024 |
| Bubble Wash & Clean Ltd | Other services | 2012 |
| Buckley Developments Ltd | Arts & recreation | 2013 |
| Buckley Transport Limited | Transport & logistics | 1999 |
| BUD Creative Limited | Wholesale & retail | 2010 |
| Buddy.Fm Ltd | Information & communication | 2024 |
| Budenberg Limited | Manufacturing | 2008 |
| Buds & Blossoms Ltd | Health & social care | 2022 |
| Buggy Dough Limited | Financial services | 2017 |
| Build in Confidence Ltd | Education | 2026 |
| Build Materials UK Limited | Wholesale & retail | 2017 |
| Build Vision Ltd | Professional & scientific | 2012 |
| Buildcare Maintenance Ltd | Construction | 2023 |
| Buildcom Developments Ltd | Construction | 2016 |
| Builders Art Limited | Construction | 2022 |
| Buildexdevelopments Ltd | Construction | 2024 |
| Building Blocks Day Nursery (NW) Limited | Health & social care | 2011 |
| Building Blocks Day Nursery (Yorkshire) Limited | Health & social care | 2025 |
| Building Materials Sorted Ltd | Wholesale & retail | 2026 |
| Buildline Plastics Ltd | Wholesale & retail | 2025 |
| Buildstore Online Ltd | Wholesale & retail | 2023 |
| Builtbymike Limited | Wholesale & retail | 2018 |
| Bullion Logistics Ltd | Transport & logistics | 2025 |
| Bullionedge FX Limited | Financial services | 2025 |
| Bullions and Coins Ltd | Wholesale & retail | 2021 |
| Bullions Online Limited | Extraterritorial | 2023 |
| Bulls Diner Ltd | Hospitality | 2026 |
| Bulstrode Park Limited | Real estate | 2016 |
| Bump, Birth, Baby & Beyond Ltd | Other services | 2023 |
| BUN and Wings Ltd | Hospitality | 2022 |
| BUN Voyage Limited | Manufacturing | 2016 |
| Bundle of Blessings Care Limited | Health & social care | 2024 |
| Bundu Consultancy Limited | Information & communication | 2014 |
| Bunkabin Limited | Administrative & support | 1988 |
| Bunkers Web Services Ltd | Information & communication | 2024 |
| Burak Shipshop Ltd | Wholesale & retail | 2024 |
| Buraqbukha Limited | Wholesale & retail | 2022 |
| Burger & Dessert Limited | Hospitality | 2022 |
| Burger Cartelz Ltd | Hospitality | 2025 |
| Burger EAT (Oldham) Ltd | Hospitality | 2026 |
| Burger Planet Ltd | Hospitality | 2024 |
| Burgereats Limited | Hospitality | 2024 |
| Burghley Financial Consultants Ltd | Professional & scientific | 2019 |
| Burgzilla Oldham Ltd | Hospitality | 2026 |
| Burito Limited | Hospitality | 2025 |
| Burke Avenue Recruitment Limited | Administrative & support | 2019 |
| Burke-E Limited | Health & social care | 2014 |
| Burlington Estates and Developments Limited | Construction | 2023 |
| Burn Farm Group Limited | Financial services | 2025 |
| Burnley Lane PO Ltd | Wholesale & retail | 2026 |
| Burscough Healthcare Limited | Wholesale & retail | 2023 |
| Bury Blinds Ltd | Wholesale & retail | 2026 |
| Bush Industries Ltd | Administrative & support | 2024 |
| Bushidokai Ltd | Other services | 2017 |
| Business Academy Network Ltd. | Professional & scientific | 2010 |
| Business Energy Solutions (U.K.) Limited | Professional & scientific | 2003 |
| Business Risk Specialists Limited | Professional & scientific | 2019 |
| Businessmen Ltd. | Administrative & support | 2016 |
| Busiwise Limited | Information & communication | 2024 |
| Busy Bears (Durham) Limited | Education | 2016 |
| Busy Bees (Durham) Limited | Education | 2016 |
| Busy Bees Clean Ltd | Administrative & support | 2025 |
| Busy Bodz Limited | Administrative & support | 2006 |
| Butler Green Limited | Wholesale & retail | 2003 |
| Butt Brothers PK Ltd | Wholesale & retail | 2025 |
| Buttercroft Homes Ltd | Real estate | 2019 |
| Butterfield & Sons Bicycles Ltd | Wholesale & retail | 2015 |
| Buxani Arosfa Hotel Limited | Hospitality | 2019 |
| Buxani Highland Hotel Limited | Hospitality | 2023 |
| Buxton ASH Ltd | Wholesale & retail | 2021 |
| Buy and Sell Caravans Ltd | Wholesale & retail | 2024 |
| Buy Anything Sell Anything Limited | Wholesale & retail | 2022 |
| Buy for Comfort Ltd | Wholesale & retail | 2026 |
| Buy Invest Ltd | Real estate | 2025 |
| Buy the Range Ltd. | Information & communication | 2021 |
| Buymoors Limited | Other services | 1993 |
| Buyonlineee Ltd | Wholesale & retail | 2026 |