| Codify Digital Ltd | Professional & scientific | 2025 |
| Coffin Club UK Ltd | Other services | 2019 |
| Colt Landscapes Ltd | Construction | 2020 |
| Combination Properties Ltd | Real estate | 2022 |
| Common Ground Psychology Ltd | Health & social care | 2025 |
| Common Land Wines Limited | Agriculture & fishing | 2026 |
| Compass Health & Social Care Consultancy Limited | Health & social care | 2016 |
| Compass Transport Ltd | Transport & logistics | 2022 |
| Compassionate Life Private Ltd | Other services | 2023 |
| Complete Fire Protection Services Ltd | Public administration | 2024 |
| Completely Novel Limited | Construction | 2008 |
| Compoundy Systems Ltd | Information & communication | 2026 |
| Connect Mortgage Services Ltd | Financial services | 2023 |
| Connect Property Holdings Ltd | Real estate | 2024 |
| Connect Property Lettings Ltd | Real estate | 2025 |
| Connor Hills Welding Services Ltd | Manufacturing | 2019 |
| Conqueror Darts Academy CIC | Arts & recreation | 2026 |
| Conquerors MC Apparel Limited | Wholesale & retail | 2020 |
| Constables Barns Limited | Agriculture & fishing | 2019 |
| Consult-Ed: Teaching&Learning Ltd | Education | 2019 |
| Conveyancing Direct Limited | Professional & scientific | 2001 |
| Copperpot Distillery Ltd | Manufacturing | 2024 |
| Corporate Securities Limited | Extraterritorial | 1964 |
| Corsham Court Residents' Association Limited | Households | 1992 |
| Corton House Management Limited | Households | 2006 |
| Court Royal Mansions Limited | Households | 1979 |
| Courtesy Call Limited | Extraterritorial | 2002 |
| Courtyard Connect Ltd | Wholesale & retail | 2019 |
| COX & Company People Development and Coaching Limited | Professional & scientific | 2013 |
| Crestbury Associates Limited | Real estate | 2001 |
| Crestbury Properties Limited | Real estate | 2005 |
| Croft Agency Ltd | Real estate | 2024 |
| Crown Abodes Limited | Households | 2022 |
| Crown Peak Holdings Ltd | Wholesale & retail | 2024 |
| Cruet House Residents' Company Limited | Households | 2021 |
| Crumpet Ltd | Wholesale & retail | 2022 |
| CS-15 Safety Solutions Ltd | Health & social care | 2022 |
| Ctech Engineering Ltd | Manufacturing | 2025 |
| Cumbia Kitchen Ltd | Hospitality | 2023 |
| Curious Agenda C.I.C. | Administrative & support | 2022 |
| Curious Camel Limited | Information & communication | 2022 |
| Cutdiamondflooring Ltd | Wholesale & retail | 2016 |
| Cutting Teeth Records Ltd | Information & communication | 2025 |
| Cuttlefish Events Ltd | Administrative & support | 2022 |
| CW Creative Ltd | Professional & scientific | 2022 |
| CWC Fifteen Ltd | Information & communication | 2025 |
| D & D Heating Sussex Ltd | Other services | 2017 |
| D Lola Social Care Consultancy Ltd | Health & social care | 2022 |
| D Snow Electrical Services Limited | Construction | 2016 |
| D.Game Emergency Electricians Ltd | Construction | 2025 |
| D2 Alternative Investments Limited | Administrative & support | 2014 |
| Dallas Chicken Limited | Hospitality | 2009 |
| Dandandora Ltd | Information & communication | 2013 |
| Dane Road Management Company Limited | Households | 2002 |
| Daniel Judd Limited | Construction | 2026 |
| Dannie-Lu Carr Creative Ltd | Professional & scientific | 2012 |
| Danny Kellys Delivery Services Limited | Transport & logistics | 2016 |
| Dark Circles Recordings Limited | Information & communication | 2025 |
| Dark Globe (the Piper) Limited | Hospitality | 2018 |
| Dashvue Ltd | Information & communication | 2026 |
| David George International Property Ltd | Real estate | 2024 |
| Dawn Estefan Creative Thinking & Thought Ltd | Health & social care | 2023 |
| Dayaw Consultancy Ltd | Information & communication | 2025 |
| DB Lift Services Limited | Construction | 2015 |
| DC Holdings Sussex Limited | Financial services | 2023 |
| DC Specialist Services Limited | Water & waste | 2017 |
| DC UK Asset Holdings Limited | Real estate | 2021 |
| Dd&Mm Ltd | Real estate | 2014 |
| DE Novo Associates Ltd | Professional & scientific | 2023 |
| Debbiemmoore Limited | Professional & scientific | 2023 |
| Decon Tech Ltd | Administrative & support | 2025 |
| Degg Properties Limited | Real estate | 2024 |
| Dementia Information & Support Courses CIC | Health & social care | 2018 |
| Dennis Building Ltd | Construction | 2024 |
| Dept of Joy Limited | Wholesale & retail | 2025 |
| Design Build Manage Ltd | Construction | 2025 |
| Design Rabbit Ltd | Wholesale & retail | 2018 |
| Design Wellness International Limited | Professional & scientific | 2021 |
| Desire Property Solutions Ltd | Households | 2019 |
| Detonics Limited | Professional & scientific | 2026 |
| Devology Ltd | Information & communication | 2014 |
| Devroom-Vantasia Limited | Information & communication | 2025 |
| DFE Contracting Ltd | Construction | 2016 |
| DFL Team Ltd | Hospitality | 2012 |
| Digital Service Book Ltd | Information & communication | 2020 |
| Dillsexpress Ltd | Wholesale & retail | 2025 |
| DJ Riga Ltd | Construction | 2026 |
| Dkss Holdings Ltd | Financial services | 2019 |
| DM Post Limited | Information & communication | 2016 |
| DMH Process Systems Ltd | Water & waste | 2020 |
| Dmjr Management Accounts Ltd | Professional & scientific | 2014 |
| DNA Technical Recruitment Limited | Professional & scientific | 2018 |
| DNA Threads Ltd | Wholesale & retail | 2025 |
| Dogs Life Rescue & Transport Ltd | Agriculture & fishing | 2024 |
| Dogs Life Rescue Ltd | Agriculture & fishing | 2022 |
| DOM Workshop Limited | Wholesale & retail | 2024 |
| Domino Inc Ltd | Financial services | 2022 |
| Dominus Solutions Ltd | Health & social care | 2025 |
| Dorevia Ltd | Information & communication | 2025 |
| Dough RAY ME Pizza Ltd | Hospitality | 2023 |