| Chenery Surveying Ltd | Professional & scientific | 2018 |
| Cherry Court RTM Company Limited | Households | 2023 |
| Cherry Lane Therapeutic Homes Ltd | Health & social care | 2024 |
| Cherry Lane Therapeutic Services Limited | Health & social care | 2020 |
| Cherry Tree Professional Limited | Professional & scientific | 2017 |
| Cherry's House of Beauty Limited | Other services | 2025 |
| Cherrytree (Wantage) Limited | Health & social care | 2014 |
| Chess House (UK) Limited | Health & social care | 2009 |
| Chester Court (Eastbourne) Management Company Limited | Households | 1977 |
| Chester Road Limited | Construction | 2020 |
| Chester Road Two Limited | Construction | 2024 |
| Chesterfield Gardens Residents Association Limited | Households | 1974 |
| Chesterfield House (Eastbourne) Management Company Limited | Households | 1977 |
| Chesters Letting Agency Limited | Real estate | 2001 |
| Chestnut Developments (London) Limited | Construction | 2011 |
| Chestnuts Jewellery Limited | Wholesale & retail | 2026 |
| Chesworth Design Ltd | Professional & scientific | 2025 |
| Cheven Limited | Wholesale & retail | 1983 |
| Chevron Business Services Limited | Professional & scientific | 1987 |
| Chichilass Ltd | Construction | 2024 |
| Chickboxing Limited | Arts & recreation | 2012 |
| Child Therapy Practitioners Ltd | Education | 2022 |
| Child Therapy Service CIC | Health & social care | 2019 |
| Childerhouse Medical Limited | Professional & scientific | 2008 |
| Children's Orthopaedic Surgery Sussex Ltd | Health & social care | 2022 |
| Chilliblossoms Limited | Administrative & support | 2017 |
| Chilling and Grilling Ltd | Hospitality | 2025 |
| Chimera Tcse Innovation Group Ltd | Manufacturing | 2023 |
| China Garden Hot Food Ltd | Hospitality | 2021 |
| CHINAINN2 Limited | Hospitality | 2026 |
| Chinese Star Eastbourne Limited | Hospitality | 2012 |
| Chiro E Solutions Limited | Information & communication | 2018 |
| Chiron Consulting Companies Ltd | Professional & scientific | 2025 |
| Chitti Enterprises Limited | Wholesale & retail | 2013 |
| Choice Marketing Limited | Professional & scientific | 2002 |
| Choice Vehicle Rentals Limited | Transport & logistics | 1998 |
| Choomar Brothers Ltd | Hospitality | 2024 |
| Chop Shop Tavern Ltd | Hospitality | 2025 |
| Chopmart Limited | Wholesale & retail | 2025 |
| Chores Cleaning ( South East) Ltd. | Administrative & support | 2014 |
| Chris Beeney Plumbing and Heating Solutions Ltd | Construction | 2014 |
| Chris Knights and Associates Limited | Professional & scientific | 2011 |
| Chris Laughton Ltd | Information & communication | 2018 |
| Christian Black Photography Limited | Professional & scientific | 2015 |
| Christian Copyright Licensing International Limited | Other services | 1991 |
| Christian Music Alliance Limited | Other services | 1986 |
| Christian Video Licensing International (Europe) Limited | Information & communication | 2001 |
| Christie & Guazir Ltd | Wholesale & retail | 2010 |
| Christies Contract Cleaners Limited | Administrative & support | 2002 |
| Christopher James Hill Limited | Health & social care | 2026 |
| Chromevalue Developments Limited | Construction | 2012 |
| CHS Electrical Limited | Construction | 1999 |
| Chukka Belts Limited | Wholesale & retail | 2018 |
| Church Projects Limited | Professional & scientific | 1990 |
| Church Street Building Ltd | Real estate | 2025 |
| Church Street Steakhouse Ltd | Hospitality | 2022 |
| Churchdale Road Management Company Limited | Households | 1989 |
| Churchfield Square Eastbourne Limited | Households | 2002 |
| Churnbusters UK Ltd | Professional & scientific | 2024 |
| Chyngton Compliance Services Limited | Professional & scientific | 2025 |
| CI Squared Limited | Wholesale & retail | 2009 |
| Cinek Limited | Information & communication | 2015 |
| Cinetica Limited | Transport & logistics | 2015 |
| Cintra House Limited | Real estate | 2003 |
| Cirkel London Ltd | Professional & scientific | 2021 |
| Cirnok Ltd | Hospitality | 2025 |
| Cisse UK Community Interest Company | Education | 2019 |
| Citkd Ltd | Arts & recreation | 2020 |
| City Address Limited | Other services | 2021 |
| City Fella Ltd | Administrative & support | 2015 |
| Citycare Consulting Services Limited | Professional & scientific | 2019 |
| Cityvine Limited | Households | 1994 |
| Civic Management Ltd | Hospitality | 2025 |
| CIVIL4D Ltd | Construction | 2018 |
| Civils Management Ltd | Construction | 2025 |
| Civimetrics Ltd | Professional & scientific | 2025 |
| Civision Group Ltd | Construction | 2023 |
| Civision UK Ltd | Other services | 2020 |
| CJF Design Projects Limited | Professional & scientific | 2011 |
| CJL Construction and Development Ltd | Construction | 2019 |
| CJS Construction South East Limited | Construction | 2017 |
| CK Dental Limited | Health & social care | 2025 |
| CK Edit Ltd | Construction | 2017 |
| CKA Architectural Limited | Professional & scientific | 2018 |
| Ckent Products Ltd | Wholesale & retail | 2023 |
| CKR Plastering & Rendering Ltd | Construction | 2025 |
| Clacy's Properties Limited | Real estate | 2019 |
| Claire Cousens Accountancy Services Limited | Professional & scientific | 2019 |
| Claire Hepworth Orthodontics Limited | Health & social care | 2021 |
| Clanricarde Sussex CIC | Financial services | 2024 |
| Clare Parter Ultrasound Services Ltd | Health & social care | 2014 |
| Claremond Construction Limited | Construction | 2000 |
| Clarence House Residents Association Limited | Households | 1990 |
| Clarendon Court Limited | Households | 2002 |
| Clarendon Property Services Limited | Construction | 2009 |
| Clarmie Ltd | Wholesale & retail | 2021 |
| Classic Architectural Mouldings Ltd | Construction | 2022 |
| Classic Car Services (Southeast) Limited | Wholesale & retail | 2018 |
| Classic Paintwork Limited | Wholesale & retail | 2013 |
| Clause and Effect Group Limited | Administrative & support | 2026 |