| Bray Lloyd Limited | Administrative & support | 2009 |
| Breo Partnership Limited | Professional & scientific | 2018 |
| Brewhouse Partners Ltd | Professional & scientific | 2024 |
| Brian Stevens Classic Cars Limited | Wholesale & retail | 2011 |
| Bridal Industry Development Ltd. | Manufacturing | 1984 |
| Bridgemore Productions Limited | Information & communication | 2025 |
| Brierley Healthcare Ltd | Health & social care | 2011 |
| Brigadier Trading Ltd | Professional & scientific | 2021 |
| Brightside Nannies Ltd | Administrative & support | 2022 |
| Brigid Films Ltd | Information & communication | 2022 |
| Brilliant Business Ltd | Professional & scientific | 2009 |
| Britcell Ltd | Manufacturing | 2022 |
| British Car Auctions Limited | Wholesale & retail | 1947 |
| Broadmind Science Limited | Professional & scientific | 2005 |
| Broadwin Holdings Ltd | Financial services | 2026 |
| Brocketts Business Park Limited | Real estate | 1999 |
| Brocks Alarms Limited | Wholesale & retail | 2016 |
| Brookdale Enterprises Limited | Real estate | 1997 |
| BS Fleet Limited | Education | 2018 |
| Buildguard Escrow Client Money Limited | Financial services | 2026 |
| Buildguard Escrow Limited | Financial services | 2026 |
| Building Solutions (South) Limited | Wholesale & retail | 2018 |
| Built for Balance Limited | Other services | 2026 |
| Bull Design Limited | Professional & scientific | 2006 |
| Burlingham Grange Management Company Limited | Households | 2005 |
| Burrell Property Investments Limited | Real estate | 1959 |
| Busby Administration Services Ltd | Administrative & support | 2016 |
| Bushido Strategy Ltd | Professional & scientific | 2021 |
| Butterwood Enterprises Limited | Extraterritorial | 2002 |
| BVH Medical Ltd | Health & social care | 2023 |
| BW Building Solutions Ltd | Construction | 2018 |
| C & F Flooring Supplies Ltd | Wholesale & retail | 2026 |
| C & L Property Holdings Ltd | Households | 2025 |
| C Davock Catering Ltd | Hospitality | 2026 |
| C Graves Butchers Ltd | Wholesale & retail | 2013 |
| C&D Ecocleaning Ltd | Administrative & support | 2022 |
| C/E Studios Ltd | Professional & scientific | 2020 |
| Caerthillian PM Ltd | Information & communication | 2024 |
| Caesars Camp Accident Repairs Limited | Wholesale & retail | 2015 |
| CAG Crux 1 Limited | Financial services | 2025 |
| CAG Crux 2 Limited | Financial services | 2025 |
| CAG Crux 3 Limited | Financial services | 2025 |
| CAG Sirius 1 Limited | Financial services | 2022 |
| CAG Sirius 2 Limited | Financial services | 2022 |
| CAG Vega 1 Limited | Financial services | 2021 |
| CAG Zeta 1 Limited | Financial services | 2022 |
| CAG Zeta 2 Limited | Financial services | 2022 |
| Cambrai Group Limited | Professional & scientific | 2023 |
| Cameron Mcwilliam Limited | Information & communication | 2025 |
| Canoe Hill Trustees Limited | Professional & scientific | 2009 |
| Canopy Medical Services Ltd | Administrative & support | 2016 |
| Cape Transport Ltd | Transport & logistics | 2024 |
| Capital Ventures Isleworth Limited | Real estate | 2020 |
| Capitol Commercial Relocations Limited | Transport & logistics | 2000 |
| Carbology Ltd | Wholesale & retail | 2024 |
| Cardmasters Limited | Manufacturing | 1994 |
| Cariffins LLP | | 2020 |
| Carland.Com Limited | Administrative & support | 2006 |
| Caron Solutions International Limited | Manufacturing | 1999 |
| Carosell Limited | Wholesale & retail | 1999 |
| Cars Doctor Limited | Other services | 2014 |
| Cartonomy Ltd | Wholesale & retail | 2021 |
| Cashmere Goose Ltd | Wholesale & retail | 2012 |
| Caspian Horse Assisted Therapy | Health & social care | 2016 |
| Cassonbeckman.Co.Uk Limited | Extraterritorial | 2003 |
| Cast Contracting Limited | Construction | 1997 |
| Catalystgtm Ltd | Administrative & support | 2025 |
| Catherine REX Consulting Limited | Administrative & support | 2024 |
| Catherine Taylor (Wokingham) Ltd | Other services | 2024 |
| Catherine Taylor Ltd | Other services | 2019 |
| Catherine Taylor Pamper Parties Ltd | Other services | 2023 |
| Catherine Taylor the Academy Ltd | Education | 2020 |
| Catman Industry Ltd | Construction | 2026 |
| Caviste Ltd | Wholesale & retail | 2015 |
| Cayambe Holdings Limited | Financial services | 2020 |
| CB Future Tech Limited | Professional & scientific | 2022 |
| CBS Business Services Ltd | Professional & scientific | 2012 |
| CCL Building Products Limited | Manufacturing | 2003 |
| CCL Construction (Group) Limited | Construction | 2013 |
| CDN Edge Consulting Ltd | Information & communication | 2022 |
| Cedar Hill Consulting Limited | Professional & scientific | 2021 |
| Celenabella Housekeeping Ltd | Administrative & support | 2022 |
| Celicourt Communications Limited | Professional & scientific | 2014 |
| Cell Supply Ltd | Wholesale & retail | 2022 |
| Cema UK Holdings Limited | Construction | 2019 |
| Centaur Investments Limited | Professional & scientific | 1999 |
| Cftwm Mission Worldwide Ltd | Manufacturing | 2024 |
| CGA Integration Limited | Construction | 1999 |
| Chambers Technology Consulting Limited | Information & communication | 2026 |
| Change Delivery Solutions Limited | Administrative & support | 2015 |
| Change Oasis Limited | Professional & scientific | 2018 |
| Charles Guiver Aviation Limited | Transport & logistics | 2019 |
| Charles Moore Ltd | Real estate | 2018 |
| Charlie LEY Coaching Ltd | Other services | 2025 |
| Charlotte Keeble Consulting Limited | Professional & scientific | 2016 |
| Charmardav Holdings Ltd | Real estate | 2025 |
| Charter Mews Management Company Limited | Households | 2003 |
| Chartlab Ltd | Information & communication | 2024 |
| Chartwell Build Ltd | Construction | 2019 |
| Cheney Construction & Landscaping Ltd | Construction | 2024 |