| Bloom Beauty RBY Ltd | Other services | 2026 |
| Bloom Edge Ltd | Professional & scientific | 2023 |
| Bloom Property Solutions Ltd | Households | 2026 |
| Bloombox Event Hire Ltd | Hospitality | 2019 |
| Bloomin' Healthy Ltd | Hospitality | 2019 |
| Blooming Limited | Professional & scientific | 2015 |
| Blooming Services Ltd | Transport & logistics | 2021 |
| Blooms at London Ltd | Wholesale & retail | 2021 |
| Bloomsbury 365 Limited | Professional & scientific | 2023 |
| Bloomsdale Care Solutions Ltd | Public administration | 2023 |
| Blosden Property Management Services Ltd | Real estate | 2020 |
| Blossom Surprise Ltd | Wholesale & retail | 2024 |
| Blossom 24 Healthcare & Training Ltd | Real estate | 2018 |
| Blossom Breeze Agriculture Ltd | Agriculture & fishing | 2024 |
| Blossom BS Ltd | Other services | 2018 |
| Blossom Pharma Ltd | Health & social care | 2025 |
| Blossomroom 1 Ltd | Hospitality | 2025 |
| Blotudcar Ltd | Transport & logistics | 2022 |
| Blow DRY Bar Property Ltd | Other services | 2019 |
| Blower Alliance Ltd | Administrative & support | 1999 |
| Bloxdent Limited | Health & social care | 2009 |
| Bloxdent OS Ltd | Health & social care | 2025 |
| Bloxdent Properties Limited | Real estate | 2018 |
| BLR Distribution Limited | Wholesale & retail | 2011 |
| Blucat Ltd | Hospitality | 2021 |
| Blue ARC Health Limited | Administrative & support | 2013 |
| Blue Atlantic Fish Bar Limited | Hospitality | 2012 |
| Blue Boar Contracts Ltd | Professional & scientific | 2011 |
| Blue Chip Park Homes Limited | Administrative & support | 2007 |
| Blue Dog International Ltd | Professional & scientific | 2019 |
| Blue Dog Management Ltd | Professional & scientific | 2010 |
| Blue Eagles Healthcare Limited | Health & social care | 2024 |
| Blue Flow Solutions Ltd | Other services | 2011 |
| Blue FOX Finance Services Ltd | Professional & scientific | 2015 |
| Blue Hawk Accountants Northampton Ltd | Professional & scientific | 2025 |
| Blue Horizon Healthcare Recruitment Ltd | Health & social care | 2026 |
| Blue Keys Limited | Real estate | 2016 |
| Blue Light Responders Ltd | Administrative & support | 2026 |
| Blue Lion UK Solutions Ltd | Construction | 2020 |
| Blue Lobster Consultancy Ltd | Education | 2020 |
| Blue Lobster Therapy Limited | Education | 2015 |
| Blue Marlin Capital Limited | Administrative & support | 2012 |
| Blue Moon Cars Ltd | Transport & logistics | 2024 |
| Blue Mouse Productions Limited | Real estate | 1995 |
| Blue Ocean Ventures Limited | Professional & scientific | 2017 |
| Blue Penguin Electrical Ltd | Construction | 2014 |
| Blue Phoenix Accounting Ltd | Professional & scientific | 2011 |
| Blue Pro Media Limited | Arts & recreation | 2000 |
| Blue RAY Properties Ltd | Construction | 2026 |
| Blue Recruitment Personnel Ltd | Administrative & support | 2017 |
| Blue Skies (UK) Limited | Manufacturing | 1997 |
| Blue Skies Fruits Limited | Manufacturing | 2025 |
| Blue Skies Holdings Limited | Manufacturing | 2000 |
| Blue Skies Homes Limited | Real estate | 2022 |
| Blue Skies International Limited | Manufacturing | 2023 |
| Blue Sky Development Ltd | Construction | 2024 |
| Blue Sky Holdings Limited | Extraterritorial | 2018 |
| Blue Squirrel Research Ltd. | Professional & scientific | 2017 |
| Blue Star Print Solutions Ltd | Manufacturing | 2014 |
| Blue Step Solutions Limited | Professional & scientific | 2010 |
| Blue Streak Marketing Limited | Professional & scientific | 2026 |
| Blue-Sonic Tech Limited | Information & communication | 2016 |
| Bluebamboo Creative Services Ltd | Information & communication | 2017 |
| Bluebear PR Limited | Professional & scientific | 2001 |
| Bluebeards Revenge Ltd | Wholesale & retail | 2023 |
| Bluebell Advice Ltd | Professional & scientific | 2021 |
| Bluebell Business Services Limited | Administrative & support | 2022 |
| Bluebell Cloud Solutions Limited | Information & communication | 2016 |
| Bluebell Financial Services Ltd | Financial services | 2019 |
| Bluebell Group Homes Ltd | Health & social care | 2023 |
| Bluebell Technology Solutions Limited | Information & communication | 2019 |
| Blueberry Portfolio Management Limited | Real estate | 2013 |
| Bluebird Transconnect Ltd | Transport & logistics | 2024 |
| Bluegrid Commercial Ltd | Professional & scientific | 2025 |
| Blueholly Limited | Health & social care | 2003 |
| Bluei.O.N. Limited | Other services | 2014 |
| Bluelight Lining Ltd | Wholesale & retail | 2021 |
| Blueline Cars Northampton Ltd | Transport & logistics | 2026 |
| Bluemotion Motors Ltd | Wholesale & retail | 2025 |
| Bluenova Ltd | Professional & scientific | 2009 |
| Bluepeaks Global Limited | Wholesale & retail | 1998 |
| Blueprint BSS Limited | Construction | 2009 |
| Blueprint Property Sourcing Limited | Real estate | 2026 |
| Blueprint ST Limited | Other services | 2026 |
| Blueray Healthcare Limited | Other services | 2015 |
| Blueridge Technologies Limited | Information & communication | 2024 |
| Bluestone 42 Limited | Professional & scientific | 2022 |
| Bluestone Hire Limited | Administrative & support | 2016 |
| Bluestone Property & Investments Limited | Real estate | 2024 |
| Bluewave International Limited | Other services | 2003 |
| Bluzala Ltd | Real estate | 2008 |
| Blythin Management Ltd | Professional & scientific | 2026 |
| BM Carpentry (Beds) Ltd | Manufacturing | 2025 |
| BM Decorators Ltd | Construction | 2025 |
| BM Services Inc Ltd | Construction | 2014 |
| Bm&Co Limited | Professional & scientific | 2017 |
| BMA Advisory Group Ltd | Professional & scientific | 2017 |
| BMB89 Ltd | Transport & logistics | 2024 |
| BMC Baits Ltd | Manufacturing | 2025 |
| BMC Heating Ltd | Construction | 2023 |