| Cheeseclaw Films Ltd | Information & communication | 2023 |
| Cheriton Court Residents Association Limited | Households | 1981 |
| Cherry Tree Dental Practice Ltd | Health & social care | 2010 |
| Chesham Close Limited | Households | 2005 |
| Chestnut Lodge Residents Association Limited | Households | 1964 |
| Chicken World Piri Piri Ltd | Wholesale & retail | 2021 |
| Chilberton Drive (23-33 ODD) Management Company Limited | Households | 2000 |
| Chilmead Residents Limited | Households | 2023 |
| Chiwy Limited | Construction | 2006 |
| Chloris Ltd | Professional & scientific | 2025 |
| Chowler Decorations Ltd | Construction | 2025 |
| Chris Mcrobbie Design Ltd | Professional & scientific | 2013 |
| Chris Plumridge Limited | Administrative & support | 2008 |
| Christian Resources Exhibitions Limited | Administrative & support | 1990 |
| Chrysalis Coaching & Development Limited | Professional & scientific | 2017 |
| Churchill Close Property Management Company Limited | Households | 2011 |
| CI2I Communications Ltd | Professional & scientific | 2026 |
| Cinderhill Ltd | Professional & scientific | 2020 |
| Cinnamon Flamehouse Ltd | Hospitality | 2025 |
| Circle Foods Limited | Wholesale & retail | 2011 |
| City Stone Ltd | Construction | 2015 |
| Citylink (Property Investments) Limited | Real estate | 1962 |
| Citylink Corporate Services Limited | Real estate | 1990 |
| Citylink Group Limited | Real estate | 1982 |
| Citysprint (UK) Group Limited | Extraterritorial | 2010 |
| Citysprint (UK) Limited | Transport & logistics | 2001 |
| Citysprint Courier Services Limited | Transport & logistics | 2006 |
| Cityweb Limited | Real estate | 2002 |
| Civil Base Ltd | Construction | 2022 |
| CJM IT Consulting Limited | Information & communication | 2018 |
| Cjsupply Ltd | Wholesale & retail | 2026 |
| Clandon Court (Sutton) Management Limited | Households | 2004 |
| Clare Payne-Hanlon Ltd | Information & communication | 2026 |
| Clarence Capital Management Limited | Professional & scientific | 2018 |
| Clares of Croydon Limited | Administrative & support | 1994 |
| Clas Networks Ltd | Administrative & support | 2025 |
| Clashfit Training Ltd | Arts & recreation | 2020 |
| Classic Antique Fairs Ltd | Arts & recreation | 2023 |
| Classic IS Key Ltd | Education | 2023 |
| CLC Construction Ltd | Manufacturing | 2025 |
| Clear Trades Group Ltd | Financial services | 2025 |
| Clearline Roofing Ltd | Construction | 2024 |
| Clearmasters (Environmental) Limited | Water & waste | 2011 |
| Clearpath Risk Advisory Ltd | Professional & scientific | 2025 |
| Clemlec Group Ltd | Construction | 2020 |
| Clemlec Heritage Limited | Construction | 2024 |
| Clemlec Limited | Construction | 2005 |
| Cleo Management Services Ltd | Administrative & support | 2011 |
| Cleverhealth Solutions Ltd | Health & social care | 2022 |
| Click&Connect Media Ltd | Professional & scientific | 2025 |
| Cliffe Consult Limited | Professional & scientific | 2020 |
| Clifton Cars Ltd | Wholesale & retail | 2025 |
| Clinical Phase Development Ltd | Professional & scientific | 2011 |
| Clip 'N Climb Crawley Limited | Arts & recreation | 2006 |
| Clockwise Marketing Ltd | Other services | 1995 |
| Cloud Orthodontics Limited | Health & social care | 2017 |
| Cloud Training Ltd | Information & communication | 2010 |
| CLOUD2ME Ltd | Information & communication | 2013 |
| Cloudevoque Limited | Information & communication | 2021 |
| Cloudspanx Limited | Information & communication | 2017 |
| Clover-Bruton Limited | Financial services | 2019 |
| Clyde Hall (Addiscombe) Limited | Real estate | 2010 |
| Co-Ordinated Engineering Limited | Construction | 1985 |
| Coco and NUT Wimbledon Ltd | Hospitality | 2023 |
| Coconut and Sticky Bear Ltd | Information & communication | 2018 |
| Coddiwomple Theatre Ltd | Arts & recreation | 2024 |
| Coffee Finance Ltd | Administrative & support | 2025 |
| Coffee Vending Solutions Ltd | Wholesale & retail | 2023 |
| Cognitive Software Limited | Information & communication | 2020 |
| Cognivate Rehab Ltd | Health & social care | 2020 |
| Cohort Teams Limited | Administrative & support | 2020 |
| Coldmist Limited | Real estate | 2009 |
| Colin Smith Planning Limited | Professional & scientific | 2013 |
| Colin Stimpson Creative Services Limited | Professional & scientific | 2020 |
| Colin Thwaites Limited | Construction | 2006 |
| Collier Commercials Limited | Wholesale & retail | 2018 |
| Collier Roofing Surrey Limited | Construction | 2014 |
| Collingtree Services Ltd | Real estate | 2023 |
| Collyer Rose Limited | Administrative & support | 2014 |
| Comac Developments Limited | Construction | 2017 |
| Comestibles Direct Ltd | Wholesale & retail | 2022 |
| Comfort Heating Wimbledon Ltd | Construction | 2026 |
| Comm Comm UK Digital Limited | Professional & scientific | 2020 |
| Comm-Motion Limited | Professional & scientific | 2007 |
| Commcomm UK Limited | Administrative & support | 2012 |
| Compare ALL Limited | Administrative & support | 2009 |
| Complete Height Safety Ltd | Construction | 2022 |
| Complete Roofing & Property Maintenance Ltd | Construction | 2025 |
| Component Knowledge Limited | Information & communication | 1998 |
| Compucare Systems Limited | Information & communication | 1995 |
| Computer Avalanche Limited | Wholesale & retail | 2024 |
| Concept Engineering Limited | Manufacturing | 1965 |
| Concept Property Management Limited | Professional & scientific | 2004 |
| Concept Property Management Secretarial Services Ltd | Administrative & support | 2016 |
| Concept Property Sales and Lettings Limited | Real estate | 2009 |
| Concerto Computing Limited | Information & communication | 2005 |
| Conexus Advisory Holding Limited | Financial services | 2017 |
| Conexus Capital Limited | Administrative & support | 2019 |
| Conexus Group Holding Limited | Financial services | 2016 |
| Connaught Gardens Residents Association Limited(The) | Households | 1985 |