| Blow & Go Limited | Other services | 2025 |
| Blowers Investment Properties Limited | Real estate | 2021 |
| Blowers Jewellers Holdings Limited | Extraterritorial | 2013 |
| Bludot Digital Limited | Information & communication | 2022 |
| Bludot Recruitment and Care Limited | Administrative & support | 2022 |
| Blue Anchor Homes Ltd | Real estate | 2024 |
| Blue Bell Inn 2 Limited | Hospitality | 2026 |
| Blue Bell Spa UK Ltd | Other services | 2026 |
| Blue Belle Developments Ltd | Real estate | 2024 |
| Blue Build (Plumbing & Heating) Ltd | Construction | 2017 |
| Blue Copper Ventures UK Ltd | Other services | 2025 |
| Blue Corner 1 Ltd | Wholesale & retail | 2026 |
| Blue Decorating Services Limited | Construction | 2014 |
| Blue Deer Business Ltd | Professional & scientific | 2018 |
| Blue Green Architecture Ltd | Professional & scientific | 2023 |
| Blue Label Investments Ltd | Real estate | 2025 |
| Blue Monkey Heating Ltd | Construction | 2022 |
| Blue Oval Creative Limited | Manufacturing | 2008 |
| Blue Platinum Properties Limited | Households | 2020 |
| Blue River Finance Limited | Professional & scientific | 2025 |
| Blue River Group (UK) Ltd | Manufacturing | 2009 |
| Blue Shop (Hull) Limited | Wholesale & retail | 2024 |
| Blue Side Studio Ltd | Professional & scientific | 2019 |
| Blue Sky Management Systems Limited | Professional & scientific | 2025 |
| Blue Star Pattern Toys Ltd | Manufacturing | 2014 |
| Blue Swan Holiday Lets Limited | Hospitality | 2021 |
| Blue Swan Properties Ltd | Construction | 2019 |
| Blue Water Training and Consultancy Limited | Education | 2016 |
| Blue@Sky Ltd | Hospitality | 2021 |
| Bluebell Residential Home Limited | Health & social care | 2002 |
| Bluelogic Properties Limited | Real estate | 2024 |
| Blueprint PC Services Limited | Professional & scientific | 2024 |
| Blueseng Limited | Manufacturing | 2009 |
| Bluesky Chair Designs Limited | Wholesale & retail | 2014 |
| Bluesky Upholstery Limited | Financial services | 2017 |
| Bluestead Ltd | Professional & scientific | 2025 |
| Bluestone Agricultural Service Ltd | Agriculture & fishing | 2024 |
| Bluestorm Design Holdings Limited | Professional & scientific | 2012 |
| Blunt the Space Limited | Other services | 2025 |
| Blush & Broom Cleaning Co. Ltd | Administrative & support | 2026 |
| Blutrust Ltd | Real estate | 2023 |
| Blyzr Limited | Professional & scientific | 2025 |
| BM Controls Ltd | Manufacturing | 2009 |
| BMB Enterprises Trading Limited | Wholesale & retail | 2018 |
| Bmce Motors Ltd | Wholesale & retail | 2024 |
| BMG CMA Ltd | Other services | 2020 |
| Bmjp Property Ltd | Real estate | 2026 |
| BMM Electrical Services Limited | Construction | 2006 |
| Bmora Ltd | Wholesale & retail | 2018 |
| BMP Solutions Limited | Other services | 1996 |
| BN Barbers Ltd | Other services | 2019 |
| BN Electrical Services Ltd | Construction | 2026 |
| BNR Taverna Ltd | Hospitality | 2025 |
| BNS Diagnostics Limited | Wholesale & retail | 2018 |
| BNT Tech Hull Ltd | Wholesale & retail | 2025 |
| Bntec German Car Sales Ltd | Wholesale & retail | 2019 |
| Bntec Hull Ltd | Wholesale & retail | 2005 |
| Boanas Estates Limited | Real estate | 2004 |
| Boardroom Beverley Ltd | Hospitality | 2025 |
| Boards Fencing Ltd | Construction | 2024 |
| Boats and Oars Ltd | Agriculture & fishing | 2025 |
| BOB Carver's Ltd | Hospitality | 2012 |
| BOB Greens Ltd | Wholesale & retail | 2011 |
| Bobi 09 Ltd | Wholesale & retail | 2018 |
| Bobs Barista and Tea Room Limited | Hospitality | 2023 |
| Bobsbeans Limited | Wholesale & retail | 2023 |
| Bocock Limited | Financial services | 2018 |
| Bode Contract Limited | Wholesale & retail | 2022 |
| Bodmin Road Church | Other services | 2008 |
| Body Boost Clinic Ltd | Health & social care | 2022 |
| Body Project Boxing & Fitness Coaching Ltd | Arts & recreation | 2019 |
| Bodyshots Vending Ltd | Wholesale & retail | 2026 |
| Boffin Limited | Professional & scientific | 2015 |
| Bogtransport Limited | Other services | 2019 |
| Boiler Maintenance GAS Services Limited | Construction | 2005 |
| Bokays Florist Ltd | Wholesale & retail | 2020 |
| BOL Energy Limited | Energy | 2025 |
| Bold Care Limited | Transport & logistics | 2022 |
| Bolek Ltd | Construction | 2025 |
| Bona Construction Limited | Manufacturing | 2025 |
| Bonbon International Ltd | Professional & scientific | 2019 |
| Boncuk Charms Limited | Wholesale & retail | 2025 |
| Bond Street Holdings LLP | | 2017 |
| Bondholderscheme Limited | Other services | 2010 |
| Bondline Industries Limited | Wholesale & retail | 2009 |
| Bone Machine Brewing Company Limited | Manufacturing | 2017 |
| Bonnie.Rlhealthcare Ltd. | Public administration | 2022 |
| Bonus Accessories Limited | Wholesale & retail | 1985 |
| Bonus Control Systems Limited | Construction | 2019 |
| Bonus Electrical Group Limited | Real estate | 1979 |
| Bonus Electrical Limited | Wholesale & retail | 1974 |
| Bonus Global Limited | Extraterritorial | 2025 |
| Bonus Power Systems Limited | Construction | 2011 |
| Bonus Securities Limited | Other services | 2002 |
| Bonus Solar Limited | Wholesale & retail | 2015 |
| Bonus Utilities Limited | Extraterritorial | 2025 |
| BOO3 Local Hull Limited | Wholesale & retail | 2026 |
| Book a Local Trade Ltd | Construction | 2019 |
| Booker Property Group Limited | Real estate | 2015 |
| Boons Bikes Limited | Wholesale & retail | 2010 |