| Black Mirror Ltd | Professional & scientific | 2009 |
| Black Palfrey Motor Club of Kent Limited | Arts & recreation | 1982 |
| Blackhawk Assets Limited | Administrative & support | 2015 |
| Blacklands Schoolyard Management Company Limited | Real estate | 2010 |
| Blackmar Limited | Financial services | 2019 |
| Blackmoorfoot (Huddersfield) Management Company Limited | Households | 2025 |
| Blade (UK) Ltd | Real estate | 1998 |
| Blaze Services (NO1) Limited | Construction | 2026 |
| BLB Properties Ltd | Real estate | 2025 |
| Blean Common Management Company Limited | Households | 2025 |
| Blighs Property Limited | Real estate | 2019 |
| Bljp Limited | Real estate | 2020 |
| Bloomsbury Gardens (Sissinghurst) Management Company Limited | Households | 2025 |
| Bloomsbury Terrace Management Limited | Households | 2009 |
| Blue Horizon Cost Consultancy Ltd | Other services | 2017 |
| Blue Ridge Transport Ltd | Transport & logistics | 2025 |
| Blue Sky Counselling Limited | Health & social care | 2023 |
| Blue Tomato Accounting Limited | Professional & scientific | 2019 |
| Bluebell Cake Design Ltd | Wholesale & retail | 2022 |
| Bluebird Trading Company 06 Limited | Transport & logistics | 2013 |
| Bluelight CRM Ltd | Information & communication | 2015 |
| Bluelight Trustees Limited | Administrative & support | 2024 |
| Blythe Park LLP | | 2017 |
| BML Building Services Ltd | Construction | 2009 |
| Bodywork Repairs (Kent) Limited | Wholesale & retail | 2024 |
| Bonnefare Limited | Real estate | 1998 |
| Bonny & Co. (Fruit Importers) Limited | Wholesale & retail | 1950 |
| Bookademix Limited | Professional & scientific | 2019 |
| Booker Wyatt Accounting Limited | Professional & scientific | 2016 |
| Boorley Green LLP | | 2015 |
| Bounsen C.I.C. | Health & social care | 2024 |
| Bovis Country Homes Limited | Professional & scientific | 1971 |
| Bovis Homes (Broadbridge Heath) Limited | Professional & scientific | 2012 |
| Bovis Homes (Quest) Company Limited | Professional & scientific | 1999 |
| Bovis Homes BVC Ltd. | Professional & scientific | 1962 |
| Bovis Homes Cambourne West LLP | | 2019 |
| Bovis Homes Cornwall Limited | Professional & scientific | 1967 |
| Bovis Homes Eastern Limited | Professional & scientific | 1946 |
| Bovis Homes Freeholds Limited | Professional & scientific | 2004 |
| Bovis Homes Insulation Limited | Professional & scientific | 1957 |
| Bovis Homes Limited | Professional & scientific | 1970 |
| Bovis Homes Midlands & Northern Limited | Professional & scientific | 1959 |
| Bovis Homes North Whiteley LLP | | 2018 |
| Bovis Homes Pension Scheme Trustee Limited | Financial services | 1997 |
| Bovis Homes Projects Limited | Professional & scientific | 1958 |
| Bovis Homes South East Limited | Professional & scientific | 1956 |
| Bovis Homes Southern Limited | Professional & scientific | 1934 |
| Bovis Homes Wessex Limited | Professional & scientific | 1933 |
| Bovis Latimer (Sherford) LLP | | 2018 |
| Bowerhouse II Solar Limited | Energy | 2019 |
| Bowleys Restaurant Limited | Hospitality | 2020 |
| Boyaca Ltd | Real estate | 2021 |
| Braaiwolf Ltd | Wholesale & retail | 2021 |
| Bradbourne House Limited | Real estate | 2008 |
| Bradwell Court (Freehold) Limited | Households | 1999 |
| Bradypus Limited | Real estate | 2017 |
| Brandifique Ltd | Professional & scientific | 2005 |
| BRE Advisory Ltd | Information & communication | 2023 |
| Brennan’S Heating Ltd | Construction | 2024 |
| Brick & Leaf Limited | Wholesale & retail | 2024 |
| Bricks & Mortar Contractors Limited | Construction | 1999 |
| Brigade Fitness Kings Hill Ltd | Education | 2021 |
| Broad Fulfillment Specialists Ltd | Wholesale & retail | 2025 |
| Broadmead Road Limited | Households | 2016 |
| Broadwater Farm Limited | Extraterritorial | 2022 |
| Brokers Wine Bar Limited | Wholesale & retail | 2004 |
| Broodcomb Press Ltd | Information & communication | 2018 |
| Brookdale Court Management Company Ltd | Households | 2022 |
| Brooklands Residents Management Company Limited | Households | 2025 |
| Brookline Developments Limited | Real estate | 2017 |
| Brookman Property Solutions Limited | Real estate | 2018 |
| Brownbush Limited | Households | 1981 |
| Bruce Turner Associates Limited | Professional & scientific | 2001 |
| Brunel Street Works Energy Services Limited | Construction | 2019 |
| Brunswick Court (Wimbledon) Limited | Households | 1996 |
| BS AS Investments Ltd | Real estate | 2024 |
| BS Events Limited | Administrative & support | 2022 |
| BSR Ltd | Construction | 2023 |
| Buckley Place Residents Management Company Limited | Households | 2025 |
| Budget Parcel Post Limited | Transport & logistics | 2013 |
| Buen Capital Limited | Financial services | 2020 |
| Build LEN Ltd | Construction | 2019 |
| Bulk Flooring Limited | Wholesale & retail | 2016 |
| Burnet Ware & Graves Surveyors Limited Liability Partnership | | 2003 |
| Burrows Management Services Ltd | Administrative & support | 2018 |
| Burton Autoworks Ltd | Wholesale & retail | 2025 |
| Bury ST Edmunds (Countryside) LLP | | 2025 |
| Bury ST Edmunds Residents Management Company Limited | Households | 2025 |
| Bush Barbering Ltd. | Other services | 2011 |
| Business Concepts HS Limited | Other services | 2017 |
| Business Elevation Coaching Ltd | Administrative & support | 2025 |
| Butt of Sherry Limited | Hospitality | 2011 |
| Bymollie Ltd | Wholesale & retail | 2020 |
| BYZ Consulting Ltd | Professional & scientific | 2016 |
| C & M Rapid Limited | Wholesale & retail | 2008 |
| C a Sports Education Ltd | Arts & recreation | 2023 |
| C S Miles Engineering Limited | Water & waste | 2016 |
| C&E Consultancy (Kent) Limited | Professional & scientific | 2024 |
| C&M Capital Ltd | Construction | 2016 |
| Cabot Credit Management Group Limited | Professional & scientific | 2003 |