| Blue Springs (Northwood) Freehold Limited | Households | 2020 |
| Bluefin Strategy Ltd | Financial services | 2023 |
| Blueprint Group Practice Ltd | Administrative & support | 2011 |
| Bluewater Group Europe Ltd | Wholesale & retail | 2017 |
| Blyss Garden Rooms Ltd | Construction | 2020 |
| Bobcat Solutions Limited | Information & communication | 2023 |
| Bockings Management Ltd | Households | 2025 |
| Boiled Frog Services Limited | Wholesale & retail | 2022 |
| Bold Data Ltd | Information & communication | 2021 |
| Boldsteps Investments Ltd | Real estate | 2020 |
| Bond & White Investments Limited | Real estate | 1929 |
| Bond Security Ltd | Administrative & support | 2017 |
| Bondcam Limited | Information & communication | 2005 |
| Bonuscover Limited | Real estate | 1993 |
| Boro Meats Ltd | Wholesale & retail | 2020 |
| Boss Plumbing and Heating Services Limited | Construction | 2007 |
| Bottega Creative Studio Ltd | Professional & scientific | 2022 |
| Bounds Green Dental Ltd | Health & social care | 2017 |
| Bourne Healthcare Ltd | Health & social care | 2007 |
| Bozi Developments Limited | Wholesale & retail | 2025 |
| Braham Associates Limited | Administrative & support | 2008 |
| Brahmbhatt Ltd | Administrative & support | 2014 |
| Bramham Court (Northwood) Limited | Households | 1989 |
| Branduin Business Support Ltd. | Administrative & support | 2011 |
| Brave Grips Limited | Information & communication | 2013 |
| Braysham Limited | Information & communication | 1999 |
| Breckner Properties Limited | Real estate | 2023 |
| Brehon Legal Limited | Professional & scientific | 2019 |
| Brent Dental Specialists Ltd | Health & social care | 2019 |
| Brew T Way Ltd | Manufacturing | 2020 |
| Brew-Itcafe Limited | Wholesale & retail | 2024 |
| Brick Brace Limited | Manufacturing | 2012 |
| Bridgeway Property Holdings Limited | Financial services | 2025 |
| Bridgeway Property Investments Ltd | Real estate | 2025 |
| Bridgeway Property Services Limited | Construction | 2005 |
| Brighter Daze Soulful Events Ltd | Administrative & support | 2025 |
| Brilliant Blessing Limited | Real estate | 2020 |
| Broadstone Technologies Limited | Information & communication | 2013 |
| Brook Century Developments Limited | Construction | 2026 |
| Brooking & Edmonds Ltd | Real estate | 2012 |
| Brooklyn Travel Holdings Limited | Administrative & support | 2018 |
| Brooklyn Travel Limited | Administrative & support | 2018 |
| Brookpark Developments Limited | Construction | 2007 |
| Broomstickmedia Ltd | Information & communication | 2023 |
| Bros Property Holdings Ltd | Construction | 2015 |
| Brown Walls Developments Limited | Construction | 2024 |
| Browns Confectionery Ltd | Wholesale & retail | 2020 |
| Brunswick Consultancy (Group) Limited | Information & communication | 2010 |
| Bryden Cottages Management Limited | Real estate | 2006 |
| Brylake Ltd | Wholesale & retail | 2021 |
| BS Express Ltd | Hospitality | 2016 |
| BS TAM Limited | Hospitality | 2024 |
| Bubbly Limited | Real estate | 2013 |
| Buckingham & Company Limited | Professional & scientific | 2011 |
| Buckley Family Property Development Limited | Households | 2025 |
| Bucks Housing Ltd | Other services | 2018 |
| Bucks Management Ltd | Other services | 2018 |
| Bugni Labs Ltd | Information & communication | 2018 |
| Build Beams Construction Limited | Construction | 2025 |
| Build Right Homes Limited | Construction | 2003 |
| Bull Star Ltd | Information & communication | 2023 |
| Bulusu Enterprises Ltd | Professional & scientific | 2024 |
| Buona Cafe Limited | Hospitality | 2000 |
| Burberry Court Management Limited | Households | 2005 |
| Burton Commercial Management Limited | Professional & scientific | 2014 |
| Bushey Property Partners LLP | | 2011 |
| Bushey Residential Limited | Construction | 2021 |
| Business First Partnership Limited | Transport & logistics | 1997 |
| Business Spirits Limited | Professional & scientific | 2019 |
| Butt Builders Limited | Administrative & support | 2015 |
| Butterflies (UK) Limited | Education | 2007 |
| Butterfly Hair Trading AS the Hair Boutique Ltd | Other services | 2020 |
| BVI Travel Ltd | Administrative & support | 2021 |
| Bvision Limited | Wholesale & retail | 2011 |
| Bvision Properties Ltd | Real estate | 2019 |
| BZ Trend Ltd | Wholesale & retail | 2022 |
| C J Kirby Limited | Construction | 2000 |
| C O'Brien Ltd | Construction | 2015 |
| C REV Limited | Wholesale & retail | 2016 |
| C S V Construction Limited | Construction | 1994 |
| Cabel 7 Ltd | Other services | 2023 |
| Cablezone Limited | Extraterritorial | 2003 |
| Caerus Homes Ltd | Real estate | 2022 |
| CAF Constructions Limited | Construction | 2007 |
| Calcott Properties Limited | Professional & scientific | 1988 |
| Calcutta Real Estate Ltd | Real estate | 2022 |
| Call.Com Telecom Limited | Information & communication | 2023 |
| Calver Lodge Freehold 2010 Limited | Real estate | 2010 |
| Calver Lodge Management Company Limited | Real estate | 2008 |
| Caly Motors Limited | Wholesale & retail | 2026 |
| Camberwell Superstores Ltd | Wholesale & retail | 2017 |
| Cambreton Limited | Real estate | 1990 |
| Camplin Bianco LLP | | 2010 |
| Camprop Limited | Real estate | 2012 |
| Canape King Limited | Wholesale & retail | 2021 |
| Canonbell Properties Ltd | Real estate | 2004 |
| Canterbury Travel (London) Limited | Administrative & support | 1970 |
| Cape Call Limited | Other services | 2021 |
| Capel Cottage Estates Ltd | Construction | 2023 |
| Capital City Recycling Ltd | Water & waste | 2018 |