| CLEANWINDOW247 Limited | Administrative & support | 2024 |
| Clear Canvas Collective C.I.C. | Arts & recreation | 2026 |
| Clear Vehicle Data Limited | Information & communication | 2011 |
| Clear Vision Coaching & Consultancy Ltd | Professional & scientific | 2023 |
| CLEAR9 Ltd | Professional & scientific | 2019 |
| Clearbridge Limited | Real estate | 1963 |
| Clearly Payroll Limited | Administrative & support | 2016 |
| Clearstone Accountants Limited | Professional & scientific | 2012 |
| Clearstone Business Services Ltd | Professional & scientific | 2010 |
| Clearstone Capital Ltd | Real estate | 2020 |
| Clearstream Consulting Limited | Administrative & support | 2016 |
| CLG Management Limited | Hospitality | 2004 |
| Clifden Investments Ltd | Real estate | 2003 |
| Cliff Court (1958) Limited | Households | 1958 |
| Clifford Dann LLP | | 2002 |
| Clifford Sales and Lettings Ltd | Real estate | 2016 |
| Clifton Road Management Company Limited | Extraterritorial | 2001 |
| Cliftonville Court Ltd | Real estate | 2019 |
| Climacrew Ltd | Information & communication | 2024 |
| Climatico Ltd | Professional & scientific | 2026 |
| Clinical Governance Solutions Ltd | Professional & scientific | 2026 |
| CLN Work Ltd | Information & communication | 2026 |
| CLO PR Limited | Professional & scientific | 2017 |
| Clocktower Cameras Limited | Wholesale & retail | 2002 |
| Clockworks Brighton Ltd | Hospitality | 2021 |
| Closeunit Property Management Limited | Households | 1989 |
| Cloud Bright Technologies Limited | Information & communication | 2021 |
| Cloud HAK Ltd | Professional & scientific | 2025 |
| Cloud Nine Compliance Ltd | Information & communication | 2024 |
| Cloud Nine Massage Ltd | Health & social care | 2019 |
| Clout Tourism Management Solutions Limited | Administrative & support | 2008 |
| Cloverdown Limited | Construction | 2012 |
| Cloveroak Wills and Estate Planning Ltd | Professional & scientific | 2017 |
| Clsa Events Ltd | Other services | 2004 |
| Club Central Limited | Professional & scientific | 2019 |
| Club Entertainment Management Limited | Administrative & support | 2005 |
| Clurichaun Ltd | Information & communication | 2010 |
| CMC Hove LLP | | 2012 |
| CMX Developments Ltd | Construction | 2021 |
| CN Services Ltd | Manufacturing | 2023 |
| CNA Edtech Ltd | Education | 2023 |
| Cnnrh Limited | Professional & scientific | 2025 |
| CNR Consulting Limited | Information & communication | 2016 |
| Coach My Career Limited | Professional & scientific | 2003 |
| Coached LDN Limited | Arts & recreation | 2026 |
| Coached' by Sgut Ltd | Arts & recreation | 2022 |
| Coachedbyla Limited | Arts & recreation | 2022 |
| Coachedfitt Ltd | Other services | 2025 |
| Coast Kitchens & Bathrooms Refurbishments Limited | Manufacturing | 2023 |
| Coastal Build & Maintenance Ltd | Construction | 2019 |
| Coastal Clearances Ltd | Water & waste | 2025 |
| Coastal Copy Limited | Professional & scientific | 2023 |
| Coastal Futures Ltd | Real estate | 2022 |
| Coastal Ground Rents Limited | Real estate | 1981 |
| Coastal Group Investments Limited | Financial services | 2024 |
| Coastal Holdings (S.C.) Limited | Construction | 1963 |
| Coastal House Shares Ltd | Real estate | 2017 |
| Coastal Tax and Accountancy Ltd | Professional & scientific | 2025 |
| Cobton Associates Ltd | Professional & scientific | 2023 |
| Cocktail Cabinet Ltd | Hospitality | 2018 |
| Coco Bene Holdings Ltd | Financial services | 2026 |
| Cocoa Pañol Ltd | Hospitality | 2022 |
| Cocobongo Content Ltd | Information & communication | 2010 |
| Cocoon Interiors Ltd | Professional & scientific | 2019 |
| Coddleston Properties Limited | Real estate | 2006 |
| Code Hove Limited | Hospitality | 2015 |
| Codeface Limited | Information & communication | 1999 |
| Coden Events Ltd | Wholesale & retail | 2020 |
| Codesign Solutions Ltd | Information & communication | 2023 |
| Codex Anatomy Ltd | Wholesale & retail | 2018 |
| Codingmaster Ltd | Education | 2018 |
| Codon Partners Ltd | Administrative & support | 2025 |
| Coed Y Source Limited | Hospitality | 2025 |
| Coffee Kick Collective Limited | Hospitality | 2025 |
| Coffee LAB Hove Ltd | Wholesale & retail | 2023 |
| Coffeepot Properties Limited | Real estate | 2015 |
| Cognify Ltd | Information & communication | 2012 |
| Cognitive AI Trading Ltd | Professional & scientific | 2025 |
| Cognitive Software Systems Ltd | Information & communication | 2024 |
| Cognitive-Ai Limited | Professional & scientific | 2018 |
| Colboro Ltd | Households | 2024 |
| Coldstream Estate Management Limited | Real estate | 2011 |
| Coldy Business Solutions Ltd | Professional & scientific | 2020 |
| Coleraine Property Group Ltd | Households | 2021 |
| Coleridge Kudu Investments Ltd | Real estate | 2026 |
| Coleridge RTM Company Limited | Households | 2022 |
| Coles Powell Group Limited | Professional & scientific | 2018 |
| Coles Powell Limited | Real estate | 2017 |
| Coles Powell Maintenance Limited | Construction | 2018 |
| Colin Cook Consulting Limited | Administrative & support | 2017 |
| Colin Ingledew Associates Limited | Construction | 2013 |
| Collab Productions Limited | Arts & recreation | 2023 |
| Collabonations Ltd | Professional & scientific | 2012 |
| COLLABOR8 Consultancy Limited | Professional & scientific | 2018 |
| Collaboratehe Ltd | Professional & scientific | 2022 |
| Collingwood & Wallace Properties Ltd | Real estate | 2022 |
| Collins Plans Limited | Professional & scientific | 2016 |
| Colman's Wharf Management Limited | Households | 1988 |
| Colour Republic Ltd | Construction | 2020 |
| Colourfast (S.E.) Limited | | 1986 |