| Burnham Builders Limited | Construction | 2019 |
| Burt Construction Ltd | Construction | 2026 |
| Business Support (Sussex) Ltd | Professional & scientific | 2006 |
| Business Transformation International UK Ltd | Information & communication | 2026 |
| Businessfithr Ltd | Professional & scientific | 2026 |
| Busyworld Limited | Construction | 2002 |
| Buttonlight Limited | Arts & recreation | 2015 |
| BW Homes (Uckfield) Ltd | Construction | 2013 |
| BY the Sword Films Limited | Arts & recreation | 2022 |
| C & C Car Paints Limited | Wholesale & retail | 2013 |
| C and D Carpets Limited | Construction | 2022 |
| C G Rowe Properties Ltd | Real estate | 2025 |
| C J a Accounting Limited | Professional & scientific | 2019 |
| C&M Asset Holding Ltd | Financial services | 2023 |
| C.S.I Canopy Survey Installation Ltd | Construction | 2019 |
| C4 Ulysses Limited | Administrative & support | 2022 |
| Cabin 4 YOU Ltd | Construction | 2021 |
| Cabwise Solutions Ltd | Transport & logistics | 2025 |
| Cader VFX Ltd | Professional & scientific | 2024 |
| Cadesign UK Limited | Professional & scientific | 2008 |
| Cahoot Limited | Administrative & support | 2003 |
| Calibre Aviation Limited | Transport & logistics | 2018 |
| Calluna Sussex Limited | Real estate | 2020 |
| Caluís Jewellery Ltd | Manufacturing | 2025 |
| Calverton Consulting Limited | Professional & scientific | 2018 |
| Calypso South Limited | Manufacturing | 2014 |
| Camden Film Co. Limited | Administrative & support | 2014 |
| Camden Television Ltd. | Information & communication | 2012 |
| Cameron Coaching Ltd | Health & social care | 2026 |
| Cameronking Limited | Real estate | 2007 |
| Camillecare Ltd | Health & social care | 2020 |
| Camper Trade Ltd | Wholesale & retail | 2026 |
| Campervanist Limited | Manufacturing | 2022 |
| Camsee Properties (Cardiff) Limited | Real estate | 2025 |
| Candour Financial Planning Limited | Financial services | 2013 |
| Canhub Software Ltd | Information & communication | 2022 |
| Canton 8 Limited | Hospitality | 2026 |
| Canvas Craft UK Limited | Manufacturing | 2026 |
| Canverse Games Ltd | Information & communication | 2017 |
| Capability Supported Employment Service Ltd | Education | 2025 |
| Capegraph Limited | Real estate | 1986 |
| Capiamo Limited | Construction | 2023 |
| Capital CP Europe Limited | Agriculture & fishing | 2016 |
| Capo Construction Limited | Professional & scientific | 2010 |
| Capstones Consulting Ltd | Professional & scientific | 2017 |
| Capsun Advisory Ltd | Professional & scientific | 2026 |
| Caracciolo Capital Limited | Education | 2026 |
| Caragon Limited | Other services | 2015 |
| Cargo Law Limited | Professional & scientific | 2024 |
| Caribbean Tourism Organisation UK and Europe | Other services | 2001 |
| Caribou Trading Company Limited | Professional & scientific | 2006 |
| Carlone Limited | Transport & logistics | 1984 |
| Carlton Main Brickworks Limited | Manufacturing | 1950 |
| Carman Investment Limited | Real estate | 2018 |
| Caroline Inspires, Elevates & Empowers Ltd | Professional & scientific | 2025 |
| Carrie Millin Ltd | Financial services | 2021 |
| Carroll Estate Agents Ltd | Real estate | 2022 |
| Carry on Travel Ltd | Administrative & support | 2024 |
| Carslake Accounting Services Ltd | Professional & scientific | 2025 |
| Carter's Catering Services Ltd | Hospitality | 2025 |
| Cartshed Limited | Real estate | 2017 |
| Caryn Wright Ltd | Arts & recreation | 2007 |
| CAS Site Services Limited | Administrative & support | 2003 |
| Cascadia Connections Ltd | Information & communication | 2015 |
| Casper Scientific Limited | Real estate | 2016 |
| Caspian Court Freehold Limited | Households | 2025 |
| Cassia Hospitality Ltd | Information & communication | 2011 |
| Cassie O Ltd | Real estate | 2024 |
| Castle Labs Ltd | Information & communication | 2024 |
| Castleman and Dean Limited | Construction | 1988 |
| Castlemont Properties Limited | Real estate | 1998 |
| Castrafeld Management Limited | Financial services | 2023 |
| Cat Property Limited | Real estate | 2016 |
| Catalyst VR UK Ltd | Information & communication | 2018 |
| Catering Gone Wild Limited | Hospitality | 2025 |
| Cats Protection Care Lottery Limited | Arts & recreation | 2019 |
| Cats Protection Enterprises Limited | Other services | 1994 |
| Cats Protection Strategies for Cats Limited | Arts & recreation | 2019 |
| Cats Protection Trustee Limited | Other services | 2008 |
| CBA Removals Ltd | Transport & logistics | 2025 |
| CBS UK Holdings Ltd | Professional & scientific | 2019 |
| CC Direct Limited | Wholesale & retail | 2024 |
| CC Sales Limited | Wholesale & retail | 2011 |
| CCE Southern Ltd | Construction | 2023 |
| CCTV42 Limited | Administrative & support | 2025 |
| CDC Associates Limited | Professional & scientific | 2022 |
| Cedar Hair Studio Limited | Extraterritorial | 2016 |
| Cedar Plumbing & Heating Ltd | Construction | 2014 |
| Celebrate Trust | Other services | 2021 |
| Celle Ltd | Hospitality | 2022 |
| Central Education Limited | Education | 2018 |
| Centre Catering Limited | Hospitality | 2017 |
| Centrefire Apparel Limited | Wholesale & retail | 2017 |
| Cenwulf Limited | Manufacturing | 2018 |
| CES Consultants Limited | Professional & scientific | 2012 |
| Cfgj Investments Limited | Financial services | 2025 |
| CG Psychology Services Ltd | Education | 2019 |
| CGL Software Solutions Ltd | Information & communication | 2022 |
| CH4 Mechanical & Electrical Services Ltd | Construction | 2015 |
| Chandler Browne Architects Ltd | Professional & scientific | 2016 |