| Boughey Gardens Tennis Club Limited | Arts & recreation | 2025 |
| Boujee’S Property Services Limited | Real estate | 2023 |
| Bouldnor Mead Management Company Limited | Real estate | 2017 |
| Boultbee Management Limited | Construction | 2012 |
| Boundless FUN Ltd | Arts & recreation | 2019 |
| Bourne Green Limited | Construction | 2010 |
| Bourne-Smith Property Co (Newport) Ltd | Real estate | 2017 |
| Bovonic UK Ltd | Wholesale & retail | 2025 |
| Bowcombe Builders Limited | Construction | 2006 |
| Bowdens Mead Management Company Limited | Households | 2005 |
| Bowen James Ltd | Construction | 2018 |
| Bowkett Electrical Holdings Limited | Financial services | 2012 |
| Bowman's Accountants Ltd | Professional & scientific | 2011 |
| Bowmor Ltd | Health & social care | 2013 |
| Box & Reach Ltd | Wholesale & retail | 2025 |
| Box of Goodness Ltd | Hospitality | 2013 |
| Boxb (Bristol) Ltd | Real estate | 2020 |
| Boxstaruk Ltd | Manufacturing | 2023 |
| Boxstuff Limited | Information & communication | 2001 |
| Boyce Group Ltd | Real estate | 2012 |
| Boyce Property Ltd | Real estate | 2013 |
| Boyce SPV 10 Ltd | Real estate | 2022 |
| Boyce SPV 11 Ltd | Real estate | 2023 |
| Boyce SPV 12 Ltd | Real estate | 2023 |
| Boyce SPV 13 Ltd | Real estate | 2023 |
| Boyce SPV 14 Ltd | Real estate | 2025 |
| Boyce SPV 2 Ltd | Real estate | 2021 |
| Boyce SPV 3 Ltd | Real estate | 2021 |
| Boyce SPV 4 Ltd | Real estate | 2022 |
| Boyce SPV 5 Ltd | Real estate | 2022 |
| Boyce SPV 6 Ltd | Real estate | 2022 |
| Boyce SPV 7 Ltd | Real estate | 2022 |
| Boyce SPV 9 Ltd | Real estate | 2022 |
| Boyce SPV Ltd | Real estate | 2021 |
| Boyinaband Ltd | Information & communication | 2016 |
| Bozoni Ltd | Hospitality | 2023 |
| BP Food NPT Limited | Wholesale & retail | 2025 |
| BR & J Partners LLP | | 2025 |
| BR Lettings Ltd | Real estate | 2026 |
| BR Store Limited | Wholesale & retail | 2021 |
| BR1 Promotions Ltd | Arts & recreation | 2021 |
| BR70ADY Properties Limited | Real estate | 2025 |
| Bracket Mate Limited | Financial services | 2024 |
| Brackla Management Company (IOW) Limited | Households | 2008 |
| Bradbury Films Limited | Administrative & support | 2009 |
| Bradford Global Enterprises Ltd | Administrative & support | 2020 |
| Braeside Commercial Property Investments Ltd | Professional & scientific | 2016 |
| Braeside Energy Ltd | Wholesale & retail | 2011 |
| Braeside Marle Properties Ltd | Real estate | 2017 |
| Braeside Property Investments Limited | Real estate | 2014 |
| Bragunewport Ltd | Hospitality | 2024 |
| Brailey Apperley Baker Ltd | Professional & scientific | 2025 |
| Braithwaite Engineers Limited | Manufacturing | 1987 |
| Brakemoore Ltd | Professional & scientific | 2019 |
| Branchuk Ltd | Transport & logistics | 2024 |
| Brandlehow's Tenants' Association Limited | Households | 1995 |
| Brandon Lettings LLP | | 2011 |
| Brandy 25 Ltd | Hospitality | 2025 |
| Branka Kukic Limited | Health & social care | 2024 |
| Branstone Management Company Limited | Households | 2023 |
| Brantons Properties Ltd | Real estate | 2021 |
| Bravo Mike Bravo Aviation Ltd | Transport & logistics | 2022 |
| Bravoolle Ltd | Transport & logistics | 2019 |
| Breadly Bakery UK Limited | Manufacturing | 2024 |
| Break for Growth Limited | Professional & scientific | 2000 |
| Breakaway & Restraint Specialists Ltd | Education | 2022 |
| Breakthrough Business Development Limited | Other services | 2019 |
| Breakthrough Global Investments Ltd. | Financial services | 2025 |
| Breakthrough Talent Ltd | Administrative & support | 2024 |
| Breathing Space Landscapes Ltd | Administrative & support | 2024 |
| Brecon Energy Limited | Manufacturing | 2015 |
| Breed's Bins Limited | Administrative & support | 2019 |
| Brendan Fleming Properties Limited | Real estate | 2015 |
| Brett@Hairlounge Limited | Other services | 2023 |
| Brew and Bites (NPT) Ltd | Hospitality | 2025 |
| Breweb Ltd | Administrative & support | 2021 |
| Brewer & Brewer (IOW) Limited | Wholesale & retail | 2011 |
| Brewquar Properties Limited | Real estate | 2025 |
| Brian LEE Golf Ltd | Wholesale & retail | 2023 |
| Brick & Wealth Holdings Ltd | Professional & scientific | 2026 |
| Brick & Wealth Ltd | Financial services | 2025 |
| Brickfields IW Limited | Other services | 2013 |
| Brickhive Properties Ltd | Real estate | 2025 |
| Bricks + Timber Developments Ltd | Construction | 2019 |
| Bridal Treasures Ltd | Wholesale & retail | 2018 |
| Bridewell Associates Limited | Professional & scientific | 2025 |
| Bridewell Consultancy Limited | Professional & scientific | 2013 |
| Bridge Talent Recruitment Ltd | Administrative & support | 2025 |
| Bridgtown Plant Limited | Construction | 1993 |
| Brighstone Landscaping Limited | Administrative & support | 1998 |
| Brighstone Property Limited | Real estate | 2018 |
| Bright Brown Services Limited | Extraterritorial | 1995 |
| Bright Brown Wealth Management Ltd | Financial services | 2016 |
| Bright Financial Affiliates Ltd | Financial services | 2014 |
| Bright Horizon Care Ltd | Health & social care | 2024 |
| Bright Sparks Childcare Limited | Health & social care | 2019 |
| Bright Star Property Group Ltd | Real estate | 2023 |
| Brighter Minds Childcare Limited | Health & social care | 2019 |
| Brightside Home Improvement Ltd | Construction | 2026 |
| Brilliant Cuts Limited | Wholesale & retail | 2004 |