| BIT Holdings Limited | Real estate | 2024 |
| Bitcoin 4 U Limited | Information & communication | 2021 |
| Bite & Go Shawarma Ltd | Hospitality | 2026 |
| Bite Network Limited | Information & communication | 2009 |
| Bitspm Ltd | Information & communication | 2023 |
| Bizion Limited | Professional & scientific | 2025 |
| Biztron (UK) Limited | Administrative & support | 2024 |
| Bizz Directions Inc Ltd | Professional & scientific | 2022 |
| Bizz Educational Consultancy Ltd | Education | 2012 |
| Bizz Recruitment Limited | Administrative & support | 2020 |
| Bizzmine UK Limited | Administrative & support | 2011 |
| BJ Jones and Sons Ltd | Construction | 2014 |
| Bjay Cuisine Ltd | Hospitality | 2024 |
| BJD Properties Ltd | Real estate | 2025 |
| BJM Digital Limited | Professional & scientific | 2023 |
| BJM Flooring Limited | Construction | 2015 |
| BJS Workshops Ltd | Education | 2025 |
| BK Holdings Limited | Financial services | 2025 |
| BK Paws Play&Stay Ltd | Other services | 2026 |
| BK Restaurants Limited | Hospitality | 2025 |
| BKM Property Investments Ltd | Real estate | 2022 |
| BKN Bars Limited | Hospitality | 2020 |
| BKW Developments Limited | Real estate | 2016 |
| BL Rigging and Rope Access Limited | Professional & scientific | 2024 |
| Blabull Management Company Limited | Households | 1976 |
| Black Balance Limited | Professional & scientific | 2021 |
| Black Barn Properties Limited | Real estate | 2023 |
| Black Bull Studios Ltd | Administrative & support | 2005 |
| Black Cabin Retreats Ltd | Hospitality | 2025 |
| Black Cat Energy Ltd | Professional & scientific | 2007 |
| Black Cat Residential Ltd | Real estate | 2023 |
| Black Giraffe Ltd | Professional & scientific | 2025 |
| Black Gold Driving School Ltd | Education | 2024 |
| Black Horse Food Emporium Limited | Hospitality | 2015 |
| Black Knights Parachute Centre Limited | Arts & recreation | 1979 |
| Black Knights Parachute Club Ltd | Arts & recreation | 2014 |
| Black Pepper Mint Food Company Ltd | Hospitality | 2011 |
| Black Powder GIN Company Ltd | Manufacturing | 2016 |
| Black Tiger Creative Limited | Wholesale & retail | 2021 |
| Blackacre Holdco Limited | Financial services | 2025 |
| Blackbrook Hall Limited | Real estate | 2016 |
| Blackbull News Limited | Wholesale & retail | 2003 |
| Blackburn Bros Limited | Wholesale & retail | 1988 |
| Blackburn Fundco Limited | Construction | 2008 |
| Blackburn Hawks Academy Limited | Arts & recreation | 2019 |
| Blackburn Holdco Limited | Construction | 2008 |
| Blackburn MX Limited | Wholesale & retail | 2021 |
| Blackburn Power Limited | Manufacturing | 2009 |
| Blackburn Properties Limited | Construction | 2016 |
| Blackburn Smilecare Limited | Health & social care | 2016 |
| Blackburn Telecom Ltd | Information & communication | 2006 |
| Blackburn’S Farm Nurseries Limited | Administrative & support | 2006 |
| Blackfords Sports and Social Club Limited | Hospitality | 2004 |
| Blackgarden Ltd | Manufacturing | 2019 |
| Blackgate Estates Ltd | Real estate | 2026 |
| Blackhorse PUB Management Company Limited | Real estate | 2025 |
| Blackhorse Recruitment Limited | Professional & scientific | 2018 |
| Blackhurst Construction Limited | Construction | 1999 |
| Blackjack Productions Limited | Information & communication | 2011 |
| Blackmill Engineering Ltd | Professional & scientific | 2013 |
| Blackpool & District Canine Society Ltd | Other services | 2013 |
| Blackpool Airrifles Limited | Wholesale & retail | 1986 |
| Blackpool Bounce Ltd | Information & communication | 2011 |
| Blackpool Circus School Community Interest Company | Arts & recreation | 2000 |
| Blackpool Cleaning Corporation Limited | Administrative & support | 2019 |
| Blackpool Local Education Partnership Limited | Construction | 2010 |
| Blackpool R&B Ltd | Wholesale & retail | 2026 |
| Blackpool Service Apartments Ltd | Hospitality | 2020 |
| Blackpool South Central Ltd | Health & social care | 2024 |
| Blackpool Stays Limited | Hospitality | 2024 |
| Blackpool Symphony Orchestra Productions Limited | Arts & recreation | 2019 |
| Blackpool, Wyre & Fylde Properties Ltd | Real estate | 2025 |
| Blackridge Investment Group Ltd | Real estate | 2021 |
| Blackrocherbals Ltd | Wholesale & retail | 2025 |
| Blackrod Taverns Ltd | Hospitality | 2019 |
| Blackstone IND Limited | Financial services | 2019 |
| Blackstone Technologies Ltd | Wholesale & retail | 2021 |
| Blackstonebsd Limited | Professional & scientific | 2016 |
| Blackwell Logistics Ltd | Transport & logistics | 2026 |
| Blackwood Estates NW Ltd | Real estate | 2024 |
| Blackwood Fire Limited | Administrative & support | 1982 |
| Blackwood Ltd | Construction | 2020 |
| Blackwright Group | Other services | 2016 |
| Blade IT Solutions Limited | Information & communication | 2017 |
| Blair Gilbert Consulting Limited | Professional & scientific | 2022 |
| Blank Canvas Investments Ltd | Professional & scientific | 2025 |
| Blank Canvas Venues Limited | Other services | 2013 |
| Blanks Apparel Limited | Wholesale & retail | 2025 |
| Blayland Limited | Hospitality | 1990 |
| Blaze Solutions Limited | Information & communication | 2007 |
| Blazin Boar Limited | Information & communication | 2018 |
| Blazing Bundles Firewood Company Ltd | Wholesale & retail | 2025 |
| Bleakley Civils Limited | Construction | 2025 |
| Bleasdale Moor and Estate Limited | Construction | 2013 |
| Blessify Ltd | Wholesale & retail | 2025 |
| Blezard Limited | Professional & scientific | 2003 |
| BLH Global Limited | Professional & scientific | 2008 |
| Blhc Westwards House Limited | Health & social care | 2004 |
| BLI Holdings Ltd | Financial services | 2024 |
| Blimey Events Limited | Arts & recreation | 2021 |