| THE Racehorse Sanctuary Ltd | Professional & scientific | 2006 |
| THE Real Gardening Company Limited | Construction | 2007 |
| THE Reality Collective Ltd | Wholesale & retail | 2025 |
| THE Redundant Coach Ltd | Other services | 2025 |
| THE Relaxed Woman Limited | Arts & recreation | 2023 |
| THE Rent Company Holdings Limited | Financial services | 2021 |
| THE RES Forum Ltd | Professional & scientific | 2010 |
| THE Return Hub Holdings Limited | Administrative & support | 2023 |
| THE Return Hub Limited | Administrative & support | 2016 |
| THE Second Cycle Ltd | Wholesale & retail | 2021 |
| THE Shelley Memorial Project Community Interest Company | Professional & scientific | 2023 |
| THE Skin Studio Sussex Ltd | Other services | 2025 |
| THE Smart IT People Limited | Information & communication | 2005 |
| THE Soundologists Limited | Education | 2026 |
| THE South of England Hickory Golf Company Limited | Administrative & support | 2024 |
| THE Southwater Infant Academy | Education | 2011 |
| THE Southwater Junior Academy | Education | 2011 |
| THE Stag Collective Ltd | Professional & scientific | 2025 |
| THE Stuntman Ltd | Arts & recreation | 2026 |
| THE Sussex Beauty Clinic Ltd | Health & social care | 2006 |
| THE Sussex Group Limited | Manufacturing | 2023 |
| THE Sussex HOG Roast Company Ltd | Hospitality | 2013 |
| THE Sussex Partnership LLP | | 2008 |
| THE Sussex Travel Company Ltd | Administrative & support | 2015 |
| THE Sussex Woodworks Limited | Construction | 2018 |
| THE TAI CHI Union for Great Britain C.I.C. | Arts & recreation | 2018 |
| THE TC Group Ltd | Wholesale & retail | 1999 |
| THE Tipsy Boar Ltd | Hospitality | 2020 |
| THE Tipsy PUB Co Ltd | Hospitality | 2020 |
| THE Transparent Conveyancing Company Ltd | Professional & scientific | 2026 |
| THE Tree MEN Sussex Ltd | Agriculture & fishing | 2024 |
| THE Truffle PIG Hythe Ltd | Wholesale & retail | 2025 |
| THE Tymz Ltd | Other services | 2017 |
| THE Ukca Doorset Company Ltd | Manufacturing | 2011 |
| THE Vale Collective Limited | Hospitality | 2025 |
| THE Vault TCG+ (Collectors Edition) Limited | Wholesale & retail | 2025 |
| THE Velo Club Godalming and Haslemere Limited | Other services | 2007 |
| THE Village Chippy Sussex Limited | Hospitality | 2021 |
| THE Walled Garden Workshop C.I.C | Other services | 2008 |
| THE Watson Practice Limited | Professional & scientific | 2020 |
| THE Wellness Panel Ltd | Health & social care | 2021 |
| THE West Sussex County Federation of Women's Institutes | Other services | 1994 |
| THE Westseaxe Company Ltd | Extraterritorial | 2023 |
| THE Whitechurch Network Limited | Financial services | 1998 |
| THE Willows (Warnham) Residents Management Company Limited | Households | 2019 |
| THE Window Wizard Horsham Ltd | Manufacturing | 2019 |
| THE Wright Hub Limited | Administrative & support | 2025 |
| THE Yellow Aeroplane Group Limited | Information & communication | 2015 |
| THE Yurt Academy Ltd | Education | 2017 |
| The-Furniture-Barn Limited | Wholesale & retail | 2025 |
| Thebigteam Limited | Information & communication | 2001 |
| Thecreativesaccountant Ltd | Professional & scientific | 2025 |
| Thefencefellas Ltd | Construction | 2025 |
| Theline Ltd | Real estate | 2020 |
| Thelton Properties Limited | Real estate | 2022 |
| Theraview Consulting Ltd | Professional & scientific | 2014 |
| Thermoplastics Group UK Ltd | Manufacturing | 2022 |
| Thetravelcampus Ltd | Education | 2025 |
| Thiago Perez Ltd | Other services | 2023 |
| Think Better Group Holdings Limited | Financial services | 2025 |
| Think Better Group Limited | Hospitality | 2011 |
| Think Better Group UK Trading Limited | Wholesale & retail | 2021 |
| Think Worksafe Ltd | Construction | 2023 |
| Thinkersth Ltd | Information & communication | 2019 |
| Thomas Janus Associates Ltd | Professional & scientific | 2014 |
| Thoms Trading Company Ltd | Professional & scientific | 2019 |
| Thorney Isle Research Ltd | Extraterritorial | 2021 |
| Thornfield Securities (Holdings) Limited | Professional & scientific | 1964 |
| Thornfield Securities Limited | Construction | 1970 |
| Thorntonsaerials Ltd | Other services | 2014 |
| Thorpe and Foster Limited | Wholesale & retail | 1970 |
| Three Case Management Limited | Health & social care | 2016 |
| Three Little Pigs Consulting Ltd | Professional & scientific | 2023 |
| Three Sisters Real Estate Ltd | Real estate | 2026 |
| Thruster Consulting Limited | Professional & scientific | 2017 |
| Thyme Solutions Ltd | Professional & scientific | 2018 |
| Tiberius Marketing Services Ltd | Professional & scientific | 2023 |
| Tick Financial Ltd | Professional & scientific | 2012 |
| Tick-Tock Consulting Limited | Professional & scientific | 2004 |
| Tidey Property Services Ltd | Construction | 2016 |
| Tidy Solutions 4U Ltd | Other services | 2015 |
| Tigerock Ltd | Arts & recreation | 2024 |
| Tiia Karoliina Limited | Manufacturing | 2007 |
| Tikidada Ltd | Extraterritorial | 2021 |
| Tikki Limited | Wholesale & retail | 2007 |
| Tileywoodman Communication Design Limited | Professional & scientific | 1989 |
| Tileywoodman Creative Limited | Professional & scientific | 2009 |
| Tilney House Management Company Limited | Households | 2019 |
| Timber Tree Services Ltd | Administrative & support | 2024 |
| Timberplan Products Limited | Agriculture & fishing | 1996 |
| Timberstones Construction Ltd | Construction | 2018 |
| Timewise Financial Limited | Financial services | 2006 |
| TIN Drum Productions Limited | Information & communication | 2005 |
| Tina & Hanny Properties Ltd | Real estate | 2023 |
| Tinston Wines & Ciders Limited | Manufacturing | 2017 |
| Tiny Toadstools Limited | Health & social care | 2025 |
| Titan Consultancy Organisation Ltd | Administrative & support | 2021 |
| Title Media Sussex Limited | Information & communication | 2016 |
| Titley Consulting Limited | Education | 2025 |
| Titsey Estate Company(The) | Mining & quarrying | 1927 |