| Caption Ltd | Wholesale & retail | 2019 |
| Capture Factory Photography Limited | Professional & scientific | 2014 |
| Car Wireless Ltd | Wholesale & retail | 2023 |
| Car-Go Systems Ltd | Information & communication | 2024 |
| Caracal Universal Limited | Wholesale & retail | 2023 |
| Carambada Cantina Ltd | Hospitality | 2026 |
| Caramella Limited | Wholesale & retail | 2014 |
| Caraselle Holdings Limited | Real estate | 2020 |
| Caraselle Limited | Manufacturing | 1982 |
| Carbon Cloud Ltd | Administrative & support | 2017 |
| Carbon Transition Associates Ltd | Professional & scientific | 2026 |
| Carbonfirefly Ltd | Information & communication | 2026 |
| Card Innovations Ltd | Financial services | 2005 |
| Carden Crescent Consultants Limited | Professional & scientific | 2014 |
| Carden Digital Marketing Limited | Information & communication | 2018 |
| Carden Hotspot Limited | Information & communication | 2018 |
| Carden I.T Services Limited | Information & communication | 2009 |
| Carden IT Group Limited | Financial services | 2017 |
| Carden Managed Print Limited | Wholesale & retail | 2018 |
| Carden Telecoms Limited | Information & communication | 2018 |
| Cardetra Ltd | Information & communication | 2026 |
| Cardigan Mansions Residents Management Limited | Households | 1986 |
| Cardigle Limited | Arts & recreation | 2008 |
| Cardio-Logical Limited | Administrative & support | 2009 |
| Care @ Robertsbridge Limited | Health & social care | 2009 |
| Care Combobulation Ltd | Manufacturing | 2024 |
| Care Connect ME Limited | Health & social care | 2010 |
| Care Home 24/7 Ltd | Administrative & support | 2025 |
| Care in Sussex Limited | Health & social care | 2025 |
| Care Label Ltd | Health & social care | 2010 |
| Care Unbound Limited | Health & social care | 2008 |
| CARE4YOU Homecare Services Ltd. | Health & social care | 2016 |
| Career Starter Limited | Education | 2020 |
| Carefree Property Limited | Administrative & support | 2002 |
| Careleaf Ltd | Health & social care | 2015 |
| Carew Lodge (Eastbourne) Freehold Company Limited | Households | 2021 |
| Carew Lodge Management Limited | Households | 1978 |
| Carey Dodd Associates Limited | Information & communication | 2012 |
| Caribbean ADR INS CIC | Professional & scientific | 2020 |
| Caribou Touring Services LLP | | 2016 |
| Carisbrooke Medical Centres Limited | Real estate | 1998 |
| Carlton Building and Preservation Services Limited | Wholesale & retail | 1984 |
| Carmichael & Co.Limited | Real estate | 1965 |
| Carmine Valley Limited | Real estate | 2023 |
| Carn Court Residents Association Limited | Households | 1988 |
| Carnaby Fish Bar Limited | Hospitality | 2024 |
| Carnaval Spirits Ltd | Wholesale & retail | 2020 |
| Carnieclines Ltd | Arts & recreation | 2024 |
| Carnival Papers Ltd | Wholesale & retail | 2024 |
| Carnwath Exchange Company Limited | Real estate | 1999 |
| Caroco Apart Hotel LLP | | 2016 |
| Carolina Blue Limited | Administrative & support | 2014 |
| Caroline Beavon Limited | Professional & scientific | 2013 |
| Caroline Matthews Limited | Other services | 2011 |
| Caroline Ward Vine Limited | Professional & scientific | 2015 |
| Carousel Project | Arts & recreation | 1987 |
| Carr Bros (Holdings) Limited | Real estate | 2017 |
| Carrington Mgmt Limited | Construction | 2015 |
| Carrot Circular Tech Limited | Administrative & support | 2025 |
| Carry Car ( UK ) Limited | Transport & logistics | 2005 |
| Carry on Caring Ltd | Public administration | 2021 |
| Carter and Follows Ltd | Wholesale & retail | 2019 |
| Carter Davey Architects LLP | | 2022 |
| Carter Electrical Services (Sussex) Ltd | Manufacturing | 2014 |
| Carter Revivals Limited | Construction | 2016 |
| Carter-Christian Limited | Hospitality | 2017 |
| Carters Carpet & Flooring Centre Limited | Wholesale & retail | 2022 |
| Carters Carpet Centre Limited | Wholesale & retail | 2016 |
| Cartographer Studios Ltd | Information & communication | 2017 |
| Cartra Limited | Real estate | 2022 |
| Cartwood Ltd | Construction | 2015 |
| Carvil UK Limited | Professional & scientific | 2025 |
| CAS Construction & Developments Ltd | Construction | 2019 |
| CAS Consulting Services Ltd | Professional & scientific | 2024 |
| Casazul Ltd | Manufacturing | 2019 |
| Casbar Limited | Households | 1982 |
| Casco Coffee Ltd | Hospitality | 2024 |
| Casecake Ltd | Manufacturing | 2024 |
| Casey Associates Limited | Administrative & support | 1992 |
| Caseyscaninecuts Limited | Other services | 2025 |
| Cask Widge Cellar Equipment Limited | Wholesale & retail | 2000 |
| Casper & Cole Limited | Hospitality | 2014 |
| Caspian Market Ltd | Information & communication | 2023 |
| Caspian Square Management Company Limited | Real estate | 1995 |
| Casselier Ltd | Hospitality | 2024 |
| Cassett Media Limited | Information & communication | 2024 |
| Cassius Consulting Ltd | Professional & scientific | 2023 |
| Cast in Stone Ltd | Hospitality | 2024 |
| Cast Iron CAD Ltd | Manufacturing | 2010 |
| Castaway School Travel Limited | Transport & logistics | 2010 |
| Castello Cleaning Services Ltd | Administrative & support | 2020 |
| Castle (Brighton) Limited | Real estate | 2017 |
| Castle House Hastings Limited | Households | 2000 |
| Castle Lodge Ludlow Limited | Information & communication | 1992 |
| Castle School Limited | Education | 2007 |
| Castle Snooker Ltd | Arts & recreation | 2014 |
| Castlebar Publishing Ltd | Real estate | 2000 |
| Castlemount Residents Limited | Households | 1964 |
| Castlewood Services One Limited | Administrative & support | 2001 |
| Castlewood Services Two Limited | Administrative & support | 2003 |