| Byte Bridges Solutions Ltd | Information & communication | 2026 |
| Bytecode Generation Ltd | Education | 2021 |
| Byteedge Technologies Ltd | Information & communication | 2024 |
| Bytes and Bricks Studio Ltd | Information & communication | 2026 |
| Byteserve Limited | Information & communication | 2014 |
| BZD Electrical Ltd | Construction | 2025 |
| BZK Tech Ltd | Wholesale & retail | 2015 |
| BZS Trading Ltd | Wholesale & retail | 2013 |
| C & C ALL Tree & Garden Care Ltd | Administrative & support | 2025 |
| C & C Maintenance Ltd | Manufacturing | 2011 |
| C & D Decorators Ltd | Construction | 2008 |
| C & D Partnership Limited | Other services | 2001 |
| C & D Properties (Bucks) Limited | Real estate | 2017 |
| C & I Ltd | Wholesale & retail | 2023 |
| C & J Building and Maintenance Limited | Construction | 2018 |
| C & M Mcclory & Co Limited | Financial services | 2018 |
| C a D Facilities (London) Limited | Construction | 2012 |
| C a L (MK) Limited | Construction | 2010 |
| C Again Cleaners Limited | Administrative & support | 2007 |
| C and D Pacifici Limited | Construction | 2022 |
| C C Leicester Limited | Construction | 2019 |
| C Cremin Carpentry Limited | Construction | 2023 |
| C E Transport Law Limited | Professional & scientific | 2016 |
| C G Howkins Limited | Wholesale & retail | 2012 |
| C Gatzen Ltd. | Health & social care | 2010 |
| C H R Care Private Limited | Public administration | 2023 |
| C Hyde Mortgage Finance Limited | Financial services | 2012 |
| C J Buildtech Limited | Manufacturing | 2019 |
| C King Boiler Engineers Limited | Other services | 2011 |
| C L Plumbing Heating Limited | Construction | 2019 |
| C M L London Ltd | Construction | 2008 |
| C P Flooring MK Limited | Construction | 2021 |
| C P O'Hara Construction Limited | Administrative & support | 2004 |
| C P Scharff Limited | Extraterritorial | 2007 |
| C Phelan Limited | Administrative & support | 2002 |
| C R James Electrical Ltd | Construction | 2014 |
| C Steadman Productions Ltd | Information & communication | 2025 |
| C T Properties (Ripon) Limited | Hospitality | 2017 |
| C World Group Ltd | Transport & logistics | 2025 |
| C&A PUB Management Ltd | Professional & scientific | 2023 |
| C&A PUBS22 Ltd | Hospitality | 2022 |
| C&B Developments Ltd | Real estate | 2024 |
| C&B Electrical Contractors Ltd | Construction | 2019 |
| C&B Renewable Energy Division Limited | Construction | 2024 |
| C&C Carpentry and Joinery Ltd | Construction | 2023 |
| C&C East Limited | Hospitality | 2017 |
| C&D Consultancy Limited | Professional & scientific | 2005 |
| C&D General Maintenance Limited | Administrative & support | 2020 |
| C&D Technologies (U.K.) Limited | Wholesale & retail | 1992 |
| C&G Doors Ltd | Manufacturing | 2024 |
| C&L United Ltd | Education | 2026 |
| C&S Bradley House Limited | Hospitality | 2026 |
| C,O and C Transport Ltd | Transport & logistics | 2025 |
| C,S&A Forrest Holdings Limited | Financial services | 2025 |
| C-Cube Group Limited | Wholesale & retail | 2024 |
| C. J. Muscat Properties Limited | Real estate | 1995 |
| C.A.E.C. Howard (Holdings) Limited | Professional & scientific | 1945 |
| C.J. Stubbings Limited | Real estate | 1975 |
| C.M.C. Machinery UK Ltd | Manufacturing | 2021 |
| C.S.R Construction 1 Ltd | Construction | 2023 |
| C.S.R Group 1 Ltd | Construction | 2025 |
| C.S.R Kitchens & Bathrooms Ltd | Other services | 2022 |
| C2WORKS Limited | Professional & scientific | 2016 |
| C4M Limited | Real estate | 2014 |
| CA Formwork Limited | Construction | 2015 |
| CA Sunset Limited | Professional & scientific | 2026 |
| CA the Home of Education Ltd | Education | 2025 |
| Caassie Healthcare Limited | Health & social care | 2024 |
| CAB & Sons Freight Solutions Limited | Transport & logistics | 2024 |
| CAB Associates Ltd | Real estate | 2024 |
| Cable COM Data Cabling Services Ltd | Information & communication | 2017 |
| Cabo Construction Company Limited | Construction | 2024 |
| Cacklewax Ltd | Wholesale & retail | 2025 |
| Cactus IT Solutions UK Ltd | Information & communication | 2021 |
| CAD CAM Projects Ltd | Manufacturing | 2018 |
| CAD Refurbishment Ltd | Construction | 2026 |
| Cadais Ltd | Professional & scientific | 2015 |
| Cade and Co LLP | | 2005 |
| Cade Signs & Graphics Limited | Manufacturing | 2002 |
| Cadence Digital Services Ltd | Professional & scientific | 2024 |
| Cadlink UK Limited | Professional & scientific | 1993 |
| Cadu Tech Limited | Information & communication | 2025 |
| CAE Couriers Limited | Transport & logistics | 2025 |
| Caemor Limited | Real estate | 2015 |
| Caerus Executive Limited | Education | 2013 |
| Caeser-Uk Limited | Wholesale & retail | 2020 |
| Cafe at Spring Cottage Limited | Hospitality | 2014 |
| Cafe Brasilia Limited | Hospitality | 2019 |
| Cafe Chaiwalaa Limited | Hospitality | 2021 |
| Cafe Emanuel Ltd | Hospitality | 2025 |
| Cafe Expresso Limited | Hospitality | 2020 |
| Cafe Expresso MK Limited | Hospitality | 2014 |
| Cafe MK Express Ltd | Hospitality | 2025 |
| Cafe Patisserie (Bradford) Ltd | Hospitality | 2018 |
| Cafe Revive Limited | Hospitality | 2022 |
| Cafexpress Limited | Extraterritorial | 2003 |
| CAI JAN UI Ltd. | Wholesale & retail | 2025 |
| CAI Zhao CRT Ltd. | Wholesale & retail | 2025 |
| Cain (Group) Limited | Professional & scientific | 2006 |
| Cairnhill Properties Ltd | Real estate | 2017 |