| Brighton Cauldron CIC | Administrative & support | 2019 |
| Brighton Electrics Ltd | Extraterritorial | 2020 |
| Brighton Event Catering Ltd | Hospitality | 2023 |
| Brighton Peacock Services M&W Ltd | Construction | 2018 |
| Brighton Sushi Ltd | Hospitality | 2017 |
| Brooks-Kellett Holdings Ltd | Real estate | 2025 |
| BTN Stays Ltd | Real estate | 2026 |
| Buildright Snagging Ltd | Construction | 2026 |
| Burger & Bird Limited | Hospitality | 2017 |
| Bushnelli's Coffee Ltd | Hospitality | 2026 |
| Butcher Bob's Ultimate Products Ltd | Manufacturing | 2018 |
| Butterflies Accounting Ltd | Professional & scientific | 2024 |
| Butterfly Nursery Limited | Education | 2007 |
| Bytepoint Technology Ltd | Professional & scientific | 2017 |
| C & L Lettings Limited | Real estate | 2007 |
| C & M Woodturning Limited | Extraterritorial | 2003 |
| C. R. Allen & Sons Ltd | Wholesale & retail | 2003 |
| Caldicotts Management Company Limited | Households | 2026 |
| Campbell Watson Property Holdings Ltd | Real estate | 2014 |
| Campbell Watson Property Services Ltd | Construction | 2003 |
| Canning Electrical (Sussex) Limited | Construction | 2019 |
| Captured Souls Ltd | Information & communication | 2024 |
| CARE2COVER Ltd | Other services | 2019 |
| Careyart Ltd | Professional & scientific | 2023 |
| Carruthers & Luck Investments Ltd | Real estate | 2021 |
| Catlynn Purcell Parker Limited | Transport & logistics | 2026 |
| Catlynn Transport Consultants Ltd | Transport & logistics | 2022 |
| Cavendish Roofing Limited | Construction | 2022 |
| CB Sergla Ltd | Professional & scientific | 2022 |
| CBL (Sussex) Limited | Professional & scientific | 2021 |
| CC Property Sourcing Ltd | Administrative & support | 2025 |
| Central Court Dog Grooming Hub Ltd | Other services | 2025 |
| Chai Cafe Ltd | Hospitality | 2025 |
| Chateau Velo Limited | Hospitality | 2022 |
| Chenic Limited | Real estate | 2011 |
| Cinemafoggraphy Ltd. | Information & communication | 2012 |
| CJA Property Investment Ltd | Real estate | 2024 |
| Clean CUT Franchise Limited | Administrative & support | 2012 |
| Clean CUT Gardening Eastbourne Limited | Extraterritorial | 2018 |
| Clean CUT Gardening Peacehaven Limited | Extraterritorial | 2019 |
| Clean CUT Gardening Uckfield Limited | Extraterritorial | 2019 |
| Clear Grasp Limited | Professional & scientific | 2020 |
| Clearfault AI Ltd | Information & communication | 2026 |
| Cliff Motors Ltd | Wholesale & retail | 2023 |
| Clutch on Wheels Ltd | Wholesale & retail | 2022 |
| CM Fitness & Training Ltd | Arts & recreation | 2022 |
| CNN & Sons Ltd | Real estate | 2026 |
| Concept Construction Limited | Construction | 2026 |
| Coral MGT Limited | Wholesale & retail | 2007 |
| Corporeal Ltd | Information & communication | 2023 |
| Country Cars Sussex Ltd | Wholesale & retail | 2016 |
| Courtyard Corporation UK Limited | Wholesale & retail | 2017 |
| CPC Construction and Civils Limited | Construction | 2024 |
| Cresta Court Peacehaven Limited | Households | 1997 |
| Cruz Developments Limited | Construction | 2015 |
| Crystal Glade Ltd | Wholesale & retail | 2025 |
| CS Design Draughting (UK) Limited | Construction | 1991 |
| Current Swim Limited | Wholesale & retail | 2022 |
| Curry Best Ltd | Hospitality | 2019 |
| Cut&Counter Ltd | Wholesale & retail | 2026 |
| CV Exec Hire Ltd | Transport & logistics | 2023 |
| D Barker Property Maintenance Ltd | Construction | 2024 |
| D P Elite Rendering Ltd | Construction | 2021 |
| D&A Homes Limited | Real estate | 2024 |
| D.M. Firearms Ltd | Other services | 2017 |
| Daisy's Dog Walking & Services Limited | Agriculture & fishing | 2025 |
| Datoob Limited | Health & social care | 2014 |
| Dawson Design Associates Limited | Professional & scientific | 2012 |
| Daxnigel Ltd | Information & communication | 2014 |
| Dbbaker Ltd | Real estate | 2026 |
| DC Werx Ltd | Manufacturing | 2023 |
| Dean Brothers Productions Limited | Information & communication | 1999 |
| Deep Serv Group Ltd | Administrative & support | 2012 |
| Dekram Developments Ltd | Real estate | 2023 |
| Derrick Estates Limited | Real estate | 2009 |
| Design & Product Ltd | Professional & scientific | 2009 |
| Design by Magic Ltd | Professional & scientific | 2022 |
| Designs in Aluminium (Holding Company) Limited | Manufacturing | 2014 |
| Designs in Aluminium Group Limited | Extraterritorial | 2014 |
| Designs in Aluminium Limited | Manufacturing | 2004 |
| Desmond REX Ltd | Wholesale & retail | 2020 |
| Development Impact LT Limited | Real estate | 2018 |
| DIA Group Limited | Other services | 2019 |
| DIA Systems International Limited | Manufacturing | 2014 |
| DIA Systems Limited | Manufacturing | 2002 |
| Dindins Petfood Ltd | Manufacturing | 2025 |
| Disability Sports Online Limited | Information & communication | 2021 |
| Dobermann Rescue Limited | Health & social care | 1984 |
| Don'T Just Records Ltd | Arts & recreation | 2022 |
| Donna Bartoli Ltd | Other services | 2020 |
| Doug Chambers Limited | Real estate | 2022 |
| DP Executive Chauffeur Ltd | Transport & logistics | 2022 |
| DR Koutsouris Aesthetics Limited | Health & social care | 2021 |
| Drew Tech Solutions Ltd | Information & communication | 2026 |
| Durbrett Ltd | Real estate | 2025 |
| E-HEALTH4U Ltd | Information & communication | 2020 |
| E.D.H Wetbelts Limited | Wholesale & retail | 2025 |
| E.R.L. Limited | Manufacturing | 1980 |
| Earth Holistic Hair Salon Ltd | Other services | 2019 |
| East Brighton Masonic Centre Limited | Other services | 1967 |