| Cherry Gates and Barriers Limited | Construction | 2004 |
| Cherry Security Company Limited | Construction | 2003 |
| Chesham Ltd | Real estate | 2026 |
| Chichester Dental Studio Ltd | Health & social care | 2018 |
| Chip Butty Trading Ltd | Hospitality | 2025 |
| Choco Loco Wholesale Ltd | Wholesale & retail | 2025 |
| Chokolate Limited | Arts & recreation | 2007 |
| Chris Britton Ltd | Administrative & support | 2025 |
| Cilantro Ltd | Administrative & support | 2021 |
| Cinecontact Productions Limited | Information & communication | 1985 |
| Cipheros Consultancy Limited | Information & communication | 2019 |
| Circadian Films Limited | Information & communication | 2018 |
| Circadian Pictures Ltd | Information & communication | 2013 |
| Circadian Productions Limited | Information & communication | 1998 |
| Citrine Productions Ltd | Arts & recreation | 2019 |
| City Road Option Limited | Real estate | 2015 |
| Civstruct Ltd | Professional & scientific | 2024 |
| CK and Jones Ltd | Administrative & support | 2008 |
| Clarence Road Developments Limited | Construction | 2016 |
| Claridx Ltd | Professional & scientific | 2026 |
| Clayton Consultants Limited | Professional & scientific | 2015 |
| Clearstone Paving Limited | Construction | 2009 |
| Clearview Plastics Limited | Construction | 1997 |
| Clearwater Media Ltd | Arts & recreation | 2019 |
| Click Clean Clothes Ltd | Other services | 2015 |
| Cloe Ltd | Real estate | 2022 |
| Cloud Engineering Ltd | Information & communication | 2023 |
| Clovis Ltd | Education | 2012 |
| Cluelight Ltd | Information & communication | 2022 |
| Clutch Pro Tour Limited | Arts & recreation | 2021 |
| CM Cars Limited | Wholesale & retail | 2015 |
| Cmzr Technologies Ltd | Information & communication | 2025 |
| Cnch Web Designs Ltd | Professional & scientific | 2025 |
| Coburn Communications Ltd | Professional & scientific | 2012 |
| Cocoa Bliss Creations Ltd | Manufacturing | 2025 |
| Coel Investments Limited | Real estate | 1935 |
| Collide Marketing Ltd | Professional & scientific | 2022 |
| Colonna Consultancy Limited | Professional & scientific | 2015 |
| Comedy of Errors Limited | Information & communication | 2025 |
| Company Restoration Services Limited | Extraterritorial | 2016 |
| Competeeasy Limited | Arts & recreation | 2015 |
| Concordia Dental Care Limited | Health & social care | 2015 |
| Confident Smile (UK) Ltd | Health & social care | 2008 |
| Context Loops Ltd | Information & communication | 2026 |
| Cook a Cat Productions Ltd | Information & communication | 2016 |
| Coordinated Projects Limited | Construction | 2022 |
| Coral Golding Ltd | Arts & recreation | 2024 |
| Corey K Design Ltd | Professional & scientific | 2016 |
| Cosa Investments Ltd | Real estate | 2025 |
| Cosmid Ltd | Professional & scientific | 2017 |
| Court Garden Events Limited | Hospitality | 2013 |
| Courtland Contracts Ltd | Construction | 2019 |
| CR Electrical Sussex Limited | Construction | 2017 |
| Craftholic UK Ltd | Wholesale & retail | 2013 |
| Craigwell Dental Practice Ltd | Health & social care | 2012 |
| Createchs Cloud Limited | Information & communication | 2019 |
| Createspace Garden Rooms Ltd | Construction | 2020 |
| Creative Property (Sussex) Limited | Real estate | 2019 |
| Creative Space Interiors Limited | Extraterritorial | 2005 |
| Creative Stack Limited | Information & communication | 2015 |
| Critter Sitter Sussex Limited | Agriculture & fishing | 2019 |
| Cromwell Mews (Burgess Hill) Management Company Limited | Households | 2002 |
| Crops NOT Shops C.I.C. | Agriculture & fishing | 2024 |
| Crouch Properties Ltd | Real estate | 2021 |
| Crowns Group Holdings Limited | Professional & scientific | 2021 |
| Crowns Mobile Bars & Events Limited | Hospitality | 2017 |
| CS Coaching and Mentoring Services Ltd | Professional & scientific | 2022 |
| Cube Consulting Ltd | Administrative & support | 2017 |
| CUMULO18 Soulutions Limited | Information & communication | 2025 |
| CW Pharma Quality Solutions Limited | Administrative & support | 2026 |
| D Cameron Electrical Services Ltd | Construction | 2016 |
| D. a. Clegg Home Improvements Ltd | Construction | 2018 |
| Dabbling Limited | Information & communication | 1990 |
| Daisy Rose Consultants Limited | Administrative & support | 2023 |
| Daisy Rose Group Limited | Construction | 2024 |
| Daisy Rose Properties Limited | Construction | 2024 |
| DAL Investment Ltd | Real estate | 2022 |
| Daniel Burton Ltd | Construction | 2014 |
| Daniel Martin Interiors Limited | Construction | 2026 |
| Daniel Osborn Consulting Limited | Information & communication | 2022 |
| Danworth Developments Limited | Construction | 2022 |
| Danworth Holdings Limited | Real estate | 1997 |
| Danworth Limited | Real estate | 2018 |
| Dapper Souls Ltd | Wholesale & retail | 2026 |
| Dapuzzol Ltd | Health & social care | 2012 |
| David Andrews Media Ltd | Administrative & support | 2004 |
| David Butcher Limited | Professional & scientific | 2016 |
| David Webb Property Maintenance Limited | Construction | 2005 |
| David Wheeler and Sons Ltd | Construction | 2012 |
| Davis Properties Limited | Real estate | 1987 |
| Dawn Benson Accountancy Ltd | Professional & scientific | 2008 |
| Dawson Exhibition Holding Limited | Financial services | 2025 |
| Dcthree Services (UK) Limited | Financial services | 2014 |
| DE Souza & Company Limited | Administrative & support | 1988 |
| DE Souza and Company LLP | | 2003 |
| DE Souza Commercial LLP | | 2006 |
| DE Souza Holdings Limited | Financial services | 2002 |
| DE Winter Boots Ltd | Wholesale & retail | 2023 |
| Dean Edwards Special Works Limited | Construction | 2016 |
| Dear Beneficiary Film Limited | Information & communication | 2016 |