| Blackwell Business Associates Ltd | Information & communication | 2017 |
| Bladeonlawn & Landscaping Ltd | Transport & logistics | 2021 |
| Blaiklock Limited | Professional & scientific | 2004 |
| Blaiklock Projects Limited | Transport & logistics | 2019 |
| Blakeney House (Stoke Poges) Residents Company Limited | Administrative & support | 2011 |
| Blakeshields Limited | Health & social care | 1997 |
| Blanco Solutions Limited | Agriculture & fishing | 2023 |
| Bland Property Services Ltd | Professional & scientific | 2024 |
| Blast-Parts (UK) Limited | Information & communication | 2002 |
| Blencora Ltd | Other services | 2019 |
| Blended Aesthetics Ltd | Other services | 2024 |
| Blessed & Happy Care Ltd | Health & social care | 2020 |
| Blessed Choice Limited | Wholesale & retail | 2024 |
| Blessed Personnel Limited | Health & social care | 2012 |
| BLESSING1 Care Ltd | Health & social care | 2020 |
| Blessingnjoro Solutions Ltd | Health & social care | 2026 |
| Bleu Construction Ltd | Construction | 2024 |
| Bleupoint Management Ltd | Real estate | 2023 |
| Blind IT Limited | Construction | 2023 |
| Blind PIG Limited | Information & communication | 2008 |
| Bliss Home Living Ltd | Wholesale & retail | 2017 |
| Blissbay Limited | Wholesale & retail | 2022 |
| Blissfulduos Ltd | Wholesale & retail | 2023 |
| Blitz Computer Ltd | Wholesale & retail | 2021 |
| Block Sprint Ltd | Information & communication | 2018 |
| Blood Sweat Skills Ltd | Wholesale & retail | 2025 |
| Bloom Serve Ltd | Information & communication | 2025 |
| Bloomfield Goodman House Ltd | Wholesale & retail | 2025 |
| Blooming Fabulous Flowers Ltd | Arts & recreation | 2018 |
| Bloomington Software Solutions Limited | Information & communication | 2014 |
| Bloomsbury Leather Ltd | Wholesale & retail | 2020 |
| Bloomwell Care Group Ltd | Health & social care | 2025 |
| Bloosprout Limited | Information & communication | 2024 |
| Bloova Limited | Manufacturing | 2013 |
| Blossom Cash & Carry Limited | Wholesale & retail | 2017 |
| Blossom Haven Nurseries Ltd | Health & social care | 2025 |
| Blossom Mart Ltd | Wholesale & retail | 2025 |
| Bloxch Services Ltd | Wholesale & retail | 2025 |
| Bluconnet Media Ltd. | Information & communication | 2022 |
| Blue Apple Healthcare Ltd | Health & social care | 2012 |
| Blue Arctic Ltd | Transport & logistics | 2017 |
| Blue Chip (Thames Valley) Ltd. | Professional & scientific | 1991 |
| Blue Diagonal Ltd | Real estate | 2019 |
| Blue Elephant Construction Consultancy Ltd | Professional & scientific | 2025 |
| Blue Group Global Ltd | Wholesale & retail | 2023 |
| Blue Horizon Equities Limited | Financial services | 2024 |
| Blue Horse Catering Ltd | Hospitality | 2022 |
| Blue Horse Removals Limited | Transport & logistics | 2025 |
| Blue Horse Transport Limited | Transport & logistics | 2021 |
| Blue Lake Holdings Ltd | Real estate | 2025 |
| Blue LID Ltd | Wholesale & retail | 2025 |
| Blue Lotus Property Ltd | Construction | 2024 |
| Blue Lotus Supported Living Ltd | Real estate | 2025 |
| Blue Lotus Vacations UK Ltd | Administrative & support | 2020 |
| Blue Motif Limited | Information & communication | 2010 |
| Blue Octopus Recruitment Limited | Administrative & support | 2009 |
| Blue Orchard Care Limited | Health & social care | 2025 |
| Blue Pyramid Properties Ltd | Real estate | 2024 |
| Blue Ring Investments Ltd | Real estate | 2025 |
| Blue Rock Asset Management Ltd | Wholesale & retail | 2024 |
| Blue Sky Property Services Ltd | Real estate | 2022 |
| Blue Star Express Ltd | Wholesale & retail | 2018 |
| Blue Star One Ltd. | Wholesale & retail | 2005 |
| Blue Star Worldwide Limited | Transport & logistics | 2018 |
| Blue Visionaries Ltd | Real estate | 2023 |
| Blue Willow Day Nursery Holmer Green Ltd | Health & social care | 2022 |
| Blue Willow Day Nursery Horlicks Quarter Ltd | Health & social care | 2023 |
| Blue Willow Day Nursery Ltd | Health & social care | 2015 |
| Blue Willow Holdings Ltd | Financial services | 2024 |
| Bluebell Property Group Ltd | Real estate | 2025 |
| Bluebell Property Limited | Real estate | 2024 |
| Bluebells Private Ltd | Administrative & support | 2025 |
| BLUEBIRDS1 Ltd | Administrative & support | 2024 |
| Bluebull Removals Ltd | Real estate | 2023 |
| Blueflag Animations Ltd | Professional & scientific | 2023 |
| Bluefox IT LLP | | 2010 |
| Bluegate Property Group Ltd | Real estate | 2025 |
| Blueharbor Lettings Limited | Real estate | 2025 |
| Bluehitech Ltd | Information & communication | 2020 |
| Bluehut Business Limited | Wholesale & retail | 2017 |
| Bluehut Logistics Ltd | Transport & logistics | 2024 |
| Bluelines Traders Limited | Wholesale & retail | 2021 |
| Bluenose Ltd | Administrative & support | 2012 |
| Blueprint Inventories Limited | Administrative & support | 2011 |
| Bluesky Home Solution Ltd | Construction | 2013 |
| Bluesky International Logistics Limited | Transport & logistics | 2019 |
| Bluethread OPS Ltd | Professional & scientific | 2025 |
| Bluewhite Ltd | Wholesale & retail | 2017 |
| Bluprint Properties Ltd | Real estate | 2019 |
| Blush Beauty Limited | Other services | 2004 |
| Blythe Bridge Local Ltd | Wholesale & retail | 2025 |
| BM Energies Ltd | Water & waste | 2025 |
| BM Mobile Care Ltd | Information & communication | 2012 |
| BM Premium Services Ltd | Hospitality | 2023 |
| BM Properties Empire Ltd | Real estate | 2025 |
| BMA Thermal Insulation Services Ltd | Construction | 2022 |
| Bmap Cavendish Ltd | Hospitality | 2023 |
| BMC Auto Limited | Wholesale & retail | 2019 |
| BMD Enterprises Ltd | Health & social care | 2023 |
| BME Imaging Limited | Administrative & support | 1979 |