| Countrymans Groundcare Ltd | Construction | 2012 |
| County Wharf Littlehampton (RTM) Limited | Households | 2010 |
| Couper Collection Sussex CIC | Arts & recreation | 2020 |
| Court Sixteen Limited | Households | 1985 |
| Courtenay Gate Lawns Limited | Households | 1988 |
| Courtenay House (Hove) Limited | Households | 1997 |
| Cove Elegance Limited | Wholesale & retail | 2025 |
| Cover Smart Limited | Other services | 2019 |
| Coverall Waste Solutions Ltd | Construction | 2017 |
| Cowboy Cosmonaut Films Limited | Information & communication | 2014 |
| Cowley Hill Advisors Limited | Real estate | 1996 |
| Cowper Street Management Ltd | Households | 2022 |
| Cowxsales Ltd | Professional & scientific | 2020 |
| COX and Company Hove Residential Ltd | Real estate | 2010 |
| CP Commercial Limited | Real estate | 2026 |
| CP Hove Ltd | Financial services | 2024 |
| Cpall Limited | Households | 1993 |
| Cpgt Consulting Ltd | Administrative & support | 2017 |
| Crabshack 2 Ltd | Hospitality | 2024 |
| Crabshack Limited | Manufacturing | 2014 |
| Crabtree Lane Developments Limited | Construction | 2022 |
| Crafters Kitchens & Bathrooms Ltd | Construction | 2017 |
| Craftwork Projects Ltd | Information & communication | 2009 |
| Craftyjane Limited | Other services | 2007 |
| Craig Ritchie & Company Limited | Professional & scientific | 2000 |
| Cranbrook Technical Group Ltd | Professional & scientific | 2020 |
| Crane Kalman Brighton Limited | Wholesale & retail | 2004 |
| Cranham Solar Limited | Energy | 2016 |
| Cranmead Ascent CIC | Health & social care | 2021 |
| Cranmead Group Limited | Professional & scientific | 2026 |
| Cranmead Limited | Health & social care | 2018 |
| Cranmead Services Limited | Real estate | 2020 |
| Crathorne Collaborative Ltd | Real estate | 2020 |
| Craymax Limited | Construction | 2017 |
| Crearty Limited | Other services | 2021 |
| Create Electrical Ltd | Construction | 2017 |
| Creatime Digital Marketing Ltd | Wholesale & retail | 2020 |
| Creative Direct Ltd | Professional & scientific | 2023 |
| Creative Roads Ltd | Professional & scientific | 2011 |
| Credit Risk Transfer Solutions Limited | Financial services | 2020 |
| Cregneish Ltd | Professional & scientific | 2016 |
| Crescent Court Residents Company (Hove) Limited | Households | 1988 |
| Crescent Moon Properties Ltd | Real estate | 2019 |
| Crestway News Limited | Wholesale & retail | 2003 |
| CRG Sutton Limited | Information & communication | 2007 |
| Crklr Limited | Professional & scientific | 2022 |
| CRL Enterprise Limited | Administrative & support | 2017 |
| Crockett Productions Ltd | Information & communication | 2024 |
| Croft Consult Ltd | Water & waste | 2021 |
| Cromwell Court (Hove) Limited | Households | 1990 |
| Cromwell Court Hove RTM Company Limited | Households | 2004 |
| Crook LOG Dental Limited | Health & social care | 2008 |
| Crossfit Hove Limited | Arts & recreation | 2013 |
| Crossgate Holdings Limited | Financial services | 2020 |
| Crow Skull Emporium Ltd | Wholesale & retail | 2021 |
| Crowding Bricks Ltd | Construction | 2015 |
| Crown & Body Care CIC | Education | 2026 |
| Crown Beverages Ltd | Wholesale & retail | 2019 |
| Crown Close (Hove) Limited | Households | 2022 |
| Crowson Fabrics Limited | Wholesale & retail | 1978 |
| Crunch Academy Ltd | Education | 2014 |
| Crunch Accounting Ltd | Professional & scientific | 2007 |
| Crunch Bookkeeping Ltd | Professional & scientific | 2019 |
| Crunch Investments and Pensions Ltd | Extraterritorial | 2014 |
| Crunch Ltd | Information & communication | 2020 |
| Crunch Project Ltd | Information & communication | 2019 |
| Crunch Umbrella Ltd | Professional & scientific | 2016 |
| CRX Holdings Limited | Financial services | 2025 |
| Cryobright Ltd | Health & social care | 2020 |
| Cryoclinics Ltd | Construction | 2011 |
| Crystal Clear Consulting & Coaching Limited | Professional & scientific | 2023 |
| CS Contracting Limited | Construction | 2026 |
| CSE Diamond Products Ltd | Manufacturing | 2013 |
| CSW8933 Ltd | Other services | 2020 |
| CT Chicken Ltd | Information & communication | 2020 |
| CT Works Ltd | Construction | 2022 |
| Cuban Heritage Ltd | Wholesale & retail | 2025 |
| Cube Properties Limited | Real estate | 1994 |
| Cufley Associates Ltd | Professional & scientific | 2009 |
| Cugas Plumbing & Heating Ltd | Construction | 2026 |
| Cuisinne Ltd | Hospitality | 2021 |
| Cultural and Religious Travel Services Limited | Administrative & support | 2015 |
| Cultural Baggage Limited | Administrative & support | 2017 |
| Cultural Experience England Ltd | Education | 2021 |
| Culture 2 Barber 1 Limited | Other services | 2024 |
| Culture Hamper Co Ltd | Wholesale & retail | 2025 |
| Culture Spark Global Limited | Professional & scientific | 2017 |
| Cummins&Hill Limited | Health & social care | 2021 |
| Cure Holding Limited | Other services | 2023 |
| Curing Rebels Ltd | Hospitality | 2021 |
| Curly's Daughter Ltd | Hospitality | 2020 |
| Currie Brothers Estates LLP | | 2011 |
| Curtis Services Group Ltd | Information & communication | 2016 |
| Curve Information Technology Limited | Information & communication | 2008 |
| Curzon House Properties Limited | | 1982 |
| Custard International UK Limited | Administrative & support | 2018 |
| Custom Healthcare Limited | Professional & scientific | 2001 |
| Custom Pharmaceuticals Limited | Manufacturing | 1979 |
| CUT to the Bone Productions Limited | Information & communication | 2022 |
| Cutting Edge Aesthetics Limited | Health & social care | 2018 |