| Bluelight Europe Limited | Wholesale & retail | 2017 |
| Blueprint Scaffolding (Commercial) Ltd | Construction | 2021 |
| Bluestone College Ltd | Education | 2017 |
| Bluewater Care Limited | Health & social care | 2017 |
| Blueworld Services Ltd | Wholesale & retail | 2025 |
| Blufftax Ltd | Administrative & support | 2026 |
| Blumoon Design Limited | Professional & scientific | 2013 |
| Bluvera Ltd | Wholesale & retail | 2025 |
| Bluwin Limited | Administrative & support | 2018 |
| BMK Pharma Ltd | Wholesale & retail | 2022 |
| Bmpc Group Limited | Professional & scientific | 2018 |
| Bmpc Services Limited | Health & social care | 2015 |
| BMS Lifting Ltd. | Administrative & support | 2015 |
| Bnode Ltd | Information & communication | 2021 |
| BNX Energy Ltd | Energy | 2021 |
| Boba N Bean Limited | Hospitality | 2025 |
| Bobby Dazzler Signs Limited | Arts & recreation | 2002 |
| Bobby Fashion Ltd | Wholesale & retail | 2012 |
| Bobby's Automotive Ltd | Wholesale & retail | 2026 |
| Bobs Drops Ltd | Wholesale & retail | 2024 |
| Bobs Oven Cleaning Services Limited | Hospitality | 2016 |
| Boco Collective Ltd | Arts & recreation | 2020 |
| Bodent Ltd | Health & social care | 2010 |
| Bodill 1850 Limited | Professional & scientific | 2015 |
| Bodill Group Limited | Financial services | 2017 |
| Bodill Partners Limited | Professional & scientific | 2004 |
| Body Evolution Huddersfield Ltd | Administrative & support | 2017 |
| Body Works 83 Ltd | Health & social care | 2025 |
| Bodymind Agency Ltd | Health & social care | 2022 |
| Boge Compressors Limited | Manufacturing | 1995 |
| Boiler Spares Ltd | Construction | 2006 |
| BOILERFIX247 Ltd | Construction | 2023 |
| Bokoboto Limited | Wholesale & retail | 2022 |
| Bold Baking Co Ltd | Manufacturing | 2025 |
| Bold MAN Ltd | Wholesale & retail | 2026 |
| Bold Oats Co Ltd | Manufacturing | 2025 |
| Bols & DRE Services Limited | Wholesale & retail | 2026 |
| Bolster Moor Farm Shop Limited | Wholesale & retail | 2014 |
| Bolt & Shuttleworth Limited | | 1925 |
| Bolt Visa Express Ltd | Wholesale & retail | 2025 |
| Boltcare Limited | Manufacturing | 2021 |
| Bolzgrobob's Various Magical Services Limited | Manufacturing | 2023 |
| Bond & Pollard Limited | Information & communication | 2008 |
| Bonnin Estates Limited | Real estate | 2025 |
| Bonus Media Ltd | Professional & scientific | 2012 |
| Book My Ryde Ltd | Transport & logistics | 2022 |
| Book My Taxi Ltd | Transport & logistics | 2025 |
| Book UP Your Life Ltd | Education | 2021 |
| Bookkeeping by Relative Limited | Professional & scientific | 2014 |
| Bookmole Ltd | Wholesale & retail | 2026 |
| Books 4 U Ltd | Education | 2000 |
| Boost Yoga CIC | Education | 2026 |
| Boost-It Services Ltd | Information & communication | 2019 |
| Booth Brothers Feedstock Limited | Manufacturing | 2017 |
| Booth Scientific Consulting Limited | Professional & scientific | 2024 |
| Boothroyd Psychological Services Ltd | Professional & scientific | 2022 |
| Boozemaster MRB Ltd | Wholesale & retail | 2024 |
| Bordaclo Ltd | Wholesale & retail | 2025 |
| Borderless Analysts Limited | Information & communication | 2025 |
| Boris & Co Barbers Ltd | Other services | 2017 |
| Bossdean Limited | Real estate | 1992 |
| Boston Distribution Ltd | Wholesale & retail | 2026 |
| Bosun MA Ltd | Professional & scientific | 2025 |
| Botfor Limited | Information & communication | 2018 |
| Botmot Ltd | Extraterritorial | 2024 |
| Boultons Holdings Limited | Real estate | 2015 |
| Boutiqi Bags Limited | Wholesale & retail | 2016 |
| Bowen's Homes Limited | Real estate | 2021 |
| Bower Skip Hire Limited | Water & waste | 2009 |
| Bowland Retreats Limited | Hospitality | 2026 |
| Bown Consulting Limited | Information & communication | 2016 |
| Bowyer Management Consultants Limited | Professional & scientific | 2018 |
| Box Motion Ltd | Information & communication | 2021 |
| Box Photographic Limited | Professional & scientific | 2013 |
| Boxd OFF Ltd | Construction | 2026 |
| Boxpower Amateur Boxing Club CIC | Arts & recreation | 2024 |
| Boxxroom Ltd | Information & communication | 2019 |
| Bozzyeyes & Fiddler Ltd | Construction | 2019 |
| BP Developments Ltd | Construction | 2016 |
| BP Scrap Metal Ltd | Wholesale & retail | 2021 |
| BPE Engineering Ltd | Professional & scientific | 2026 |
| BPM Tech Group UK Limited | Administrative & support | 2019 |
| BPM Tech Holdings UK Limited | Financial services | 2017 |
| BPM Tech Limited | Administrative & support | 2012 |
| BQP Limited | Real estate | 2021 |
| BR Metals Ltd | Manufacturing | 2020 |
| BR Traders Ltd | Wholesale & retail | 2024 |
| BR Winding Services Limited | Manufacturing | 2013 |
| BR02OWN Holdco Ltd | Financial services | 2026 |
| Brackenhall Community Trust Ltd | Arts & recreation | 2006 |
| Brad Prep Limited | Extraterritorial | 2007 |
| Bradbury Investments Limited | Real estate | 1998 |
| Bradbury Trading Co Ltd | Construction | 2006 |
| Bradfield Developments Limited | Construction | 2003 |
| Bradford PCH Limited | Hospitality | 2021 |
| Bradley Mills Property Ltd | Real estate | 2018 |
| Bradley Park Properties Limited | Real estate | 2026 |
| Bradley Woods Management Company (NO.1) Limited | Administrative & support | 1990 |
| Bradleys Building Limited | Hospitality | 2019 |
| Bradshaw Wholesale Limited | Wholesale & retail | 2002 |