| Crowborough Locomotive Society | Arts & recreation | 1996 |
| Crowborough MOT Station Ltd | Wholesale & retail | 2021 |
| Crowborough News Ltd | Information & communication | 2025 |
| Crowborough Pet Supplies Ltd | Wholesale & retail | 2025 |
| Crowborough Properties Limited | Real estate | 2024 |
| Crowborough Shoe Repairs Ltd | Other services | 2012 |
| Crowborough Spice Limited | Hospitality | 2026 |
| Crowborough Vehicle Hire Limited | Administrative & support | 2012 |
| Crowborough Warren Road Company Limited | Households | 1959 |
| CT Isaac Limited | Financial services | 2025 |
| CTB Carpentry & Building Ltd. | Construction | 2015 |
| CTP Engineering Solutions Limited | Professional & scientific | 2022 |
| Curd Media Limited | Information & communication | 2015 |
| Curno Holdings Ltd | Financial services | 2025 |
| Cyboron Property Ltd | Real estate | 2025 |
| D Block Films Limited | Information & communication | 2008 |
| D Dorrington Carpets Limited | Other services | 2006 |
| D J Financial Services Limited | Professional & scientific | 2007 |
| D&C Collections Ltd | Other services | 2018 |
| D.S. Services (UK) Limited | Construction | 1997 |
| DAB Chimney Sweep Services Ltd | Administrative & support | 2026 |
| DAB Hand Productions Limited | Information & communication | 2008 |
| DAB Services Ltd | Construction | 2018 |
| Daclus Woodworks Ltd | Manufacturing | 2018 |
| Danark Electrical Limited | Construction | 2010 |
| Danbury Limited | Construction | 2017 |
| Daniboy Limited | Professional & scientific | 2009 |
| Daniel Reeve Window Cleaning Ltd | Administrative & support | 2019 |
| Dark Alley Graphics Limited | Arts & recreation | 2014 |
| Dark Heart Publishing Ltd | Information & communication | 2022 |
| Darkmaster Ltd | Arts & recreation | 2018 |
| Datum Tools Limited | Manufacturing | 1994 |
| Davey HR Consulting Limited | Administrative & support | 2026 |
| David Coughlin Consultancy Limited | Administrative & support | 2009 |
| David Physio and Sports Clinic Limited | Health & social care | 2013 |
| Davis Connect UK Limited | Financial services | 2020 |
| Davis Estate Management Ltd | Real estate | 2020 |
| Davis Produce Limited | Wholesale & retail | 2005 |
| Davis Rail Engineering Limited | Construction | 2014 |
| Davis Worldwide Limited | Wholesale & retail | 2005 |
| Dawsons (Sussex) Limited | Transport & logistics | 2003 |
| DE Jong UK Ltd | Wholesale & retail | 2022 |
| Deckhandsolutions Ltd | Wholesale & retail | 2026 |
| Dencare Limited | Health & social care | 2013 |
| Denovoresearch Limited | Professional & scientific | 2023 |
| Deus Global Ltd | Manufacturing | 2025 |
| Develostates Investments Limited | Real estate | 1964 |
| Dexfox Ltd | Real estate | 2025 |
| Dextra Consulting Limited | Professional & scientific | 2020 |
| DF Accountancy Limited | Professional & scientific | 2013 |
| Diamond & Associates Ltd | Hospitality | 2016 |
| Diamond Interior Contracts LLP | | 2013 |
| Didgeman Ltd | Real estate | 2026 |
| Digit-Point Ltd | Information & communication | 2025 |
| Digital Development Exchange Ltd | Information & communication | 2025 |
| Direct Trade Plastics Limited | Wholesale & retail | 2009 |
| Distributed Technology Limited | Extraterritorial | 2005 |
| Ditigo Projects Ltd | Professional & scientific | 2013 |
| Divine Plumbing and Heating Limited | Construction | 2013 |
| Dolwen Solutions Ltd | Information & communication | 2023 |
| Donaldson West (Crowborough) Limited | Real estate | 2018 |
| Donaldson West LLP | | 2010 |
| Donamaria Ltd | Hospitality | 2019 |
| Donna Properties Limited | Real estate | 2024 |
| Draxxus Direct Limited | Professional & scientific | 2003 |
| Dreamtracker Limited | Real estate | 2004 |
| Drexsell Newman Limited | Professional & scientific | 1979 |
| Dropzone-Brewery Limited | Manufacturing | 2021 |
| DTM Print Limited | Wholesale & retail | 2021 |
| DU Maurier Limited | Information & communication | 1993 |
| Duck Valley Capital Limited | Real estate | 2021 |
| Duncan Mclaren Limited | Professional & scientific | 2022 |
| Duncan Place Park Ltd | Construction | 2022 |
| Dwellwise Ltd | Real estate | 2022 |
| E Maria Limited | Health & social care | 2023 |
| E&L Property Investments Ltd | Financial services | 2026 |
| Eaglewalk Limited | Manufacturing | 1999 |
| Earlglaze Limited | Construction | 1983 |
| Earlswood Self Storage Ltd | Other services | 2021 |
| Earth Cubs Ltd | Information & communication | 2019 |
| Eastern Spring Supplies Ltd | Wholesale & retail | 2014 |
| EBB Holiday Rentals Limited | Real estate | 2021 |
| Eclipsed Pilates Ltd | Arts & recreation | 2026 |
| Eden Hearing Ltd | Health & social care | 2013 |
| Eden Valley Builders Limited | Construction | 2023 |
| Eden Valley Interiors Limited | Wholesale & retail | 2019 |
| Education for ALL Consultancy Limited | Education | 2020 |
| Education Safeguarding Services Limited | Education | 2025 |
| Edwards & Ward Limited | Hospitality | 1999 |
| EIA Ltd | Professional & scientific | 2012 |
| Eidikos Communications Ltd | Administrative & support | 2018 |
| Eleven 17 Consulting Ltd | Information & communication | 2019 |
| Ella Developments (South East) Limited | Professional & scientific | 2020 |
| Ella Nancy FAY Ltd | Information & communication | 2025 |
| Elli MAE Soft Furnishings Ltd | Wholesale & retail | 2014 |
| Ellipsis Learning Ltd. | Education | 2015 |
| Ellora Wealth and Investments Limited | Professional & scientific | 2023 |
| Elphick Management Services Ltd | Households | 1998 |
| Elysium Limited | Information & communication | 1991 |
| Elysium Property Marketing Ltd | Professional & scientific | 2013 |