| Buildall Ltd | Construction | 2023 |
| Buildfx Limited | Construction | 2015 |
| Building Associates (London) Ltd | Construction | 2004 |
| Building Resource Hub Limited | Professional & scientific | 2020 |
| Buildwright Rendering Developments Limited | Construction | 2024 |
| Built IT Design Ltd | Construction | 2025 |
| Bukay Limited | Health & social care | 2015 |
| Bulahomes Ltd | Construction | 2022 |
| Bull & Bull Limited | Financial services | 2018 |
| Bullet Film and Television Ltd. | Information & communication | 2012 |
| Bullstone Limited | Real estate | 2021 |
| Bured Financing Limited | Administrative & support | 2020 |
| Burgate Fire Limited | Administrative & support | 2017 |
| Burgate Holdings Ltd | Real estate | 2020 |
| Burgate Plumbing & Heating Limited | Construction | 2005 |
| Burgate Productions Limited | Administrative & support | 2023 |
| Burgrantay Homes Limited | Real estate | 2024 |
| Burroughs Life Skills Support Ltd | Arts & recreation | 2007 |
| Burt and Travica Limited | Construction | 1980 |
| Burton Court RTM Company Limited | Hospitality | 2004 |
| Burtons Property Ltd | Real estate | 2025 |
| Business of Beauty Limited | Arts & recreation | 2016 |
| Business Operations Solutions Limited | Construction | 2022 |
| BUT GOD Ltd | Manufacturing | 2026 |
| Butler & Hall Limited | Administrative & support | 2012 |
| Butler Badminton Academy Ltd | Arts & recreation | 2025 |
| Buyback Solutions Limited | Wholesale & retail | 2025 |
| Bvtc Ltd | Information & communication | 2018 |
| BWM Waste Management Ltd | Water & waste | 2025 |
| BWT Construction South East Ltd | Construction | 2018 |
| BY Mario - Decking&Fencing Ltd | Construction | 2024 |
| BY Milo Limited | Wholesale & retail | 2014 |
| BY Pass Travel & Transport Ltd | Transport & logistics | 2020 |
| Bypass Entertainment Ltd | Information & communication | 2025 |
| C & C Security Limited | Administrative & support | 2023 |
| C & L Scenery Limited | Construction | 2022 |
| C and a Salons Ltd | Professional & scientific | 2025 |
| C and C 54 Management Limited | Administrative & support | 2019 |
| C and K Rental Property Limited | Real estate | 2023 |
| C Brahm Properties Ltd | Real estate | 2025 |
| C Cooper Consultants Limited | Construction | 2026 |
| C D Quinn Building Services Limited | Construction | 2019 |
| C E Gemmell Plumbing and Drainage Ltd | Construction | 2016 |
| C J Grimes Recruitment Services UK Limited | Administrative & support | 2023 |
| C J Love Wholesale Limited | Wholesale & retail | 2018 |
| C Markham Electrical Limited | Construction | 2016 |
| C Quinn Electrical and Building Services Limited | Construction | 2015 |
| C&G Fire Ltd | Construction | 2023 |
| C&O Engineering London Ltd | Wholesale & retail | 2024 |
| C.Andrewsrx Ltd | Health & social care | 2026 |
| C.G.C Carpentry Limited | Construction | 2022 |
| C.L.T.C. Ltd | Extraterritorial | 2005 |
| C10 Flooring Ltd | Administrative & support | 2020 |
| C2C Heating Solutions Ltd | Construction | 2022 |
| CAB Care Centre Limited | Wholesale & retail | 2015 |
| Cablesheer Construction Limited | Construction | 1984 |
| Cablesheer Environmental Ltd | Extraterritorial | 2012 |
| Cablesheer Group Limited | Financial services | 2012 |
| Cablesheer Limited | Construction | 2002 |
| Cabling Technologies Limited | Extraterritorial | 2009 |
| Cacio E Pepe Ristorante Italiano Limited | Hospitality | 2019 |
| Cadence AI Ltd | Information & communication | 2025 |
| Cadnan Ltd | Real estate | 2023 |
| Cafe Express (Kent) Limited | Hospitality | 2024 |
| Calibre Office Furniture & Interiors Ltd | Wholesale & retail | 1999 |
| Calibre Properties South East Limited | Administrative & support | 2016 |
| Calipi Limited | Transport & logistics | 2024 |
| Callavaco Ltd | Professional & scientific | 2019 |
| Calm RAY Ltd | Information & communication | 2011 |
| CAM Drone Services Limited | Professional & scientific | 2014 |
| CAM Service Solutions Limited | Extraterritorial | 2014 |
| CAM Specialist Support Limited | Administrative & support | 1999 |
| Cambridge Van Leyden Limited | Professional & scientific | 1994 |
| Cameo Print Finishers Limited | Manufacturing | 2001 |
| Camosi Ltd | Professional & scientific | 2025 |
| Campbell James Limited | Administrative & support | 2012 |
| CAN Baba Kebab Ltd | Hospitality | 2025 |
| Candy Aestheticsx Ltd | Administrative & support | 2023 |
| Candy Media Limited | Administrative & support | 2023 |
| Cantium Project Management Limited | Professional & scientific | 2025 |
| CAP D' Ambre Vanille Limited | Administrative & support | 2019 |
| Capala Swim Limited | Wholesale & retail | 2022 |
| Cape Wood Limited | Professional & scientific | 2018 |
| Capital Antique Services Ltd | Administrative & support | 2022 |
| Capital Commissioning Limited | Professional & scientific | 2023 |
| Capital Planning & Property Limited | Real estate | 2026 |
| Capital Transport Planning Ltd | Construction | 2017 |
| Capitoul Consulting Limited | Professional & scientific | 2022 |
| Capsitech Limited | Information & communication | 2013 |
| Capybara Holiday Limited | Administrative & support | 2024 |
| Car Crash 25 Ltd | Information & communication | 2025 |
| Carat Monkey Ltd | Real estate | 2026 |
| Carbon Eight Associates Limited | Real estate | 2019 |
| Carbonred Limited | Professional & scientific | 2002 |
| Carbonspring (Sidcup) Limited | Construction | 2016 |
| Care Staff South East Ltd. | Administrative & support | 2017 |
| Carey Electrical Contracts Limited | Construction | 2013 |
| Carey Family Holding Limited | Financial services | 2017 |
| Carey Fire Safety Limited | Public administration | 2025 |
| Carisbrooke (Sidcup) Management Limited | Households | 1981 |