| Campus Training Limited | Education | 1999 |
| Cannadines Ltd | Wholesale & retail | 2009 |
| Canterbury Engineering Associates Limited | Construction | 2009 |
| Capaxia UK Ltd | Professional & scientific | 2016 |
| Cape Marketing Agency Ltd | Professional & scientific | 2023 |
| Carbon Strategy Partners Ltd | Information & communication | 2025 |
| Cardinal Cleaning Limited | Other services | 2019 |
| Cardinal Direct Limited | Transport & logistics | 2019 |
| Cardinal Investments Limited | Construction | 2009 |
| Cardinal Media Consulting Ltd | Information & communication | 2016 |
| Cardinal North END Limited | Other services | 2016 |
| Cardinal Port Studios Limited | Real estate | 2016 |
| Cardinal Property Limited | Real estate | 2018 |
| Cardinal Trading Limited | Wholesale & retail | 2018 |
| Care Solved Ltd. | Health & social care | 2020 |
| Carruthers & Luck Limited | Professional & scientific | 2007 |
| CAS Data & Insights Ltd | Information & communication | 2025 |
| Casa Manor Homes Ltd | Real estate | 2024 |
| Casciano Limited | Construction | 1996 |
| Casserly & Sons Limited | Agriculture & fishing | 2005 |
| Catcarz (24) Ltd | Wholesale & retail | 2024 |
| Cave Retro Ltd | Manufacturing | 2016 |
| Cedarcroft (Heathfield) Limited | Real estate | 2007 |
| Celestialcraftspells Ltd | Wholesale & retail | 2025 |
| Celltech UK Battery Solutions Limited | Wholesale & retail | 2002 |
| Celltech UK Group Ltd | Wholesale & retail | 2026 |
| Celtic Coffins & Keepsakes Ltd | Wholesale & retail | 2024 |
| Central Focus Group Ltd | Wholesale & retail | 2024 |
| Centurion (Sussex) Limited | Administrative & support | 2013 |
| CGC (CG) Ltd | Construction | 2023 |
| CGM Services Limited | Manufacturing | 2015 |
| Changing Health Limited | Education | 2015 |
| Channon Consultants LLP | | 2010 |
| Chariots Chauffeurs Ltd | Other services | 2009 |
| Charlotte Brake Limited | Wholesale & retail | 2017 |
| Chatfield Close (Cooksbridge) Management Limited | Households | 2018 |
| Chatfield Close Management Company Limited | Households | 2017 |
| Chelford Fabrics Limited | Wholesale & retail | 1999 |
| Chelford Property Investment Company Limited | Administrative & support | 2010 |
| Chemandy Electronics Limited | Manufacturing | 2012 |
| Cheriton Freehold Ltd | Households | 2015 |
| Cherry Carp Ltd | Wholesale & retail | 2015 |
| Cherry Internet Limited | Information & communication | 2013 |
| Cherwell Court Management Co. Limited | Professional & scientific | 1993 |
| Chesterfield Property Investments Limited | Real estate | 1996 |
| Chickenshed Studio Limited | Manufacturing | 2025 |
| Chidd Golf Limited | Arts & recreation | 2023 |
| Chiddingfold Golf Developments Limited | Construction | 2015 |
| Children's Respite Trust | Health & social care | 2010 |
| Chillax Hotels Ltd | Hospitality | 2017 |
| Chillingham Classics Limited | Wholesale & retail | 2014 |
| Chiron International Ltd | Administrative & support | 2022 |
| Chiswick Marketing Limited | Professional & scientific | 2015 |
| Choicebet (UK) Limited | Arts & recreation | 2013 |
| Chotai Brothers Limited | Real estate | 2015 |
| Chotai Partnership Limited | Real estate | 2014 |
| Choux Patisserie Ltd | Manufacturing | 2025 |
| Christiantraverswriter Limited | Professional & scientific | 2023 |
| Christopher ROW Ltd | Administrative & support | 2024 |
| Chubb Safes Pension Trustees Limited | Professional & scientific | 2000 |
| Church Close Burgess Hill Limited | Households | 2016 |
| Church Marks Green Management Company Limited | Households | 2008 |
| CJM Projects Ltd | Construction | 2015 |
| Clara Business Ltd | Financial services | 2022 |
| Clarity HD Limited | Administrative & support | 2006 |
| Classic Hospitality Limited | Administrative & support | 2008 |
| Clearway Aviation Ltd | Transport & logistics | 2025 |
| Click Assessment Ltd | Information & communication | 2022 |
| Cloud Development and Services Ltd | Information & communication | 2022 |
| Cloudhoppers | | 1992 |
| Club Redundo Limited | Administrative & support | 2025 |
| Cluequest Ltd | Manufacturing | 2013 |
| CNC Metal Designs Ltd | Manufacturing | 2020 |
| CNG Land Limited | Construction | 2024 |
| Co-Production Housing Group Ltd | Construction | 2021 |
| Coach Catalyst Limited | Professional & scientific | 2026 |
| Coatesy Ltd | Wholesale & retail | 2018 |
| Codified Holdings Ltd | Information & communication | 2025 |
| Colorful Goblin Ltd. | Extraterritorial | 2020 |
| Colours Building Ltd | Construction | 2017 |
| Communication Technology Limited | Professional & scientific | 1999 |
| Competition Classics Ltd. | Manufacturing | 2016 |
| Complete Tool Limited | Wholesale & retail | 2013 |
| Concept Screens Limited | Construction | 2013 |
| Connections International Limited | Professional & scientific | 2008 |
| Construction CDM Services Limited | Administrative & support | 2018 |
| Constructive Heritage LLP | | 2015 |
| Consultants in Construction Limited | Construction | 2017 |
| Cooksbridge Property Group Ltd | Real estate | 2021 |
| Coolibri Ltd. | Professional & scientific | 2015 |
| Coolland Limited | Real estate | 1982 |
| Corner Court Management Company Limited | Households | 2004 |
| Corporate Entertainment Company Limited | Administrative & support | 1995 |
| Corsage Ltd | Information & communication | 2021 |
| Cotter Solutions Limited | Extraterritorial | 2025 |
| Countryworks Isfield Limited | Administrative & support | 2002 |
| Coverwize UK Ltd | Other services | 2025 |
| COX Fencing & Gates Ltd | Administrative & support | 2021 |
| Cox's K9 Cuts Ltd | Other services | 2022 |
| Craft of Communication Limited | Professional & scientific | 2007 |