| Celex Foods Limited | Wholesale & retail | 2011 |
| Celia’S Place Ltd | Real estate | 2021 |
| Cello Talent Limited | Administrative & support | 2025 |
| Cement Admixtures Association Limited | Other services | 1963 |
| Cementation Management Limited | Professional & scientific | 1946 |
| CEN Property Ltd | Real estate | 2021 |
| Cenna Consultancy Limited | Professional & scientific | 2026 |
| Centaur Associates Limited | Professional & scientific | 2013 |
| Centaury Consulting Limited | Information & communication | 2019 |
| Centipede Productions Limited | Information & communication | 2004 |
| Central Hertfordshire Ymca | Other services | 1996 |
| Central Investment Assets Ltd | Real estate | 2021 |
| Central Pozole Limited | Hospitality | 2024 |
| Centre for Global Civility Ltd | Health & social care | 2025 |
| Centre of Research in Just Transitions CIC | Professional & scientific | 2024 |
| Centric Entertainment Limited | Information & communication | 2008 |
| Centricflow Ltd | Information & communication | 2020 |
| Centurion Heights Management Co Ltd | Households | 2022 |
| Centurion Performance Solutions Limited | Professional & scientific | 2013 |
| Century Court Property Management Limited | Real estate | 2014 |
| Century Electrical Contractors Limited | Construction | 2013 |
| Cepco UK Ltd | Hospitality | 2019 |
| Ceragon (UK) Limited | Professional & scientific | 2010 |
| Ceragon Networks (UK) Limited | Information & communication | 1999 |
| Cerbul Carpatin Limited | Hospitality | 2015 |
| Certti Entertainment Ltd | Hospitality | 2021 |
| Cerulean Days Limited | Information & communication | 2015 |
| Cervantes-Knox Arbitration Ltd | Administrative & support | 2023 |
| CES Green Ltd | Energy | 2023 |
| CES International Ltd | Professional & scientific | 2018 |
| Cevlik Barber Ltd | Other services | 2024 |
| Ceylon Drops Limited | Manufacturing | 2026 |
| Cezarone Limited | Professional & scientific | 2021 |
| CF & Triton Freight Ltd | Transport & logistics | 2023 |
| CF Analytics Ltd | Construction | 2025 |
| CF Bacchus Intermediate Holdco Limited | Financial services | 2020 |
| CF Civil Engineering Limited | Construction | 2016 |
| CFE Investments Ltd | Real estate | 2023 |
| Cfms Analytics Ltd | Information & communication | 2024 |
| CG Medical Services & Training Ltd | Health & social care | 2025 |
| CGC Logistics Ltd | Transport & logistics | 2022 |
| CGG Properties Limited | Real estate | 2018 |
| CGO Limited | Administrative & support | 2017 |
| CH Drainage UK Ltd | Water & waste | 2022 |
| Chaconia Consulting Solutions Ltd | Administrative & support | 2023 |
| Chadha Capital Investments Limited | Administrative & support | 2015 |
| Chadwick Hill Econsulting Ltd | Professional & scientific | 2014 |
| Chagcrest Healthcare Limited | Wholesale & retail | 2019 |
| Chagcrest Limited | Wholesale & retail | 1982 |
| Chai Khana Watford Limited | Hospitality | 2025 |
| Chaii Shack Ltd | Hospitality | 2024 |
| Chainstech Consulting Limited | Information & communication | 2021 |
| Chakar Holdings Ltd | Financial services | 2025 |
| Chakar Pharmaceutical Witney Ltd | Wholesale & retail | 2025 |
| Chakardar | Arts & recreation | 2004 |
| Chakrabarti Limited | Health & social care | 2024 |
| Chalfont Taverns Limited | Hospitality | 2017 |
| Chalk Films Ltd | Information & communication | 2006 |
| Chalk Hill House Ltd | Health & social care | 2021 |
| Chalk Hill Property Ltd | Households | 2021 |
| Challenge - Tennis LLP | | 2015 |
| Chambers Consultants UK Limited | Professional & scientific | 2002 |
| Chameleon HR Limited | Administrative & support | 2015 |
| Chameleon IT Consultants Ltd | Information & communication | 2012 |
| Champion Europe Limited | Wholesale & retail | 2002 |
| Champion Marketing Ltd | Professional & scientific | 2025 |
| Champions CUT Ltd | Other services | 2025 |
| Chanabellas Ltd | Information & communication | 2012 |
| Chancellor House Management (Hyde Park Gate) Limited | Households | 1960 |
| Chanceway Limited | Real estate | 1986 |
| Chandra Wills Limited | Real estate | 2017 |
| Change Management and Transformation Limited | Professional & scientific | 2018 |
| Chansurt Internet Online Limited | Information & communication | 2022 |
| Chantry Architects Limited | Professional & scientific | 2016 |
| Chaplin Multimedia Limited | Information & communication | 1997 |
| Chapter 01 Limited | Wholesale & retail | 2023 |
| Chapters Brand Group Limited | Wholesale & retail | 2023 |
| Character 48 Consulting Ltd | Professional & scientific | 2024 |
| Charge Utilities Ltd | Construction | 2025 |
| Charkhi Properties Ltd | Real estate | 2024 |
| Charles & Charles Property Limited | Hospitality | 2007 |
| Charles Stephen Bourne Limited | Professional & scientific | 2022 |
| Charlie PAY Plumbing Services Ltd | Construction | 2019 |
| Charnwood Refurbishment Limited | Construction | 2024 |
| Chartbind Limited | Professional & scientific | 2010 |
| Charter Housing Partners Ltd | Hospitality | 2026 |
| Charter Property Development Limited | Construction | 2013 |
| Charterhouse Financial Accountants Ltd | Professional & scientific | 2013 |
| Charterhouse Financial Advice Ltd | Professional & scientific | 2021 |
| Charziclean Limited | Administrative & support | 2025 |
| Chase Farm (Tunbridge Wells) Limited | Real estate | 2023 |
| Chase Noble Engineering Limited | Administrative & support | 2014 |
| Chase Suenos Limited | Professional & scientific | 2012 |
| Chatsworth Homes Garboldisham Ltd | Hospitality | 2022 |
| Chatsworth Manor (Ruislip) Management Company Limited | Other services | 2005 |
| Chatsworth Mews Enterprise Ltd | Households | 2024 |
| Chaturika Jewellery Limited | Wholesale & retail | 2025 |
| Chaucer House (ST Albans) Limited | Households | 2016 |
| Chauffeur Solutions (UK) Limited | Transport & logistics | 2011 |
| Chavda Limited | Professional & scientific | 2007 |