| T.K.O. Marketing Consultants Limited | Professional & scientific | 1996 |
| TAB Trading Limited | Professional & scientific | 2016 |
| Tacit Legal LLP | | 2022 |
| TAG Care Plus Limited | Administrative & support | 2020 |
| Talent Spotters Limited | Administrative & support | 2026 |
| Talenthal.Consult Ltd | Administrative & support | 2022 |
| Taliesin International Ltd | Wholesale & retail | 2020 |
| Talisman Jewels Ltd | Wholesale & retail | 2024 |
| Talking Travel Ltd | Financial services | 2019 |
| Tallypro Limited | Professional & scientific | 2005 |
| Tamarind Media Limited | Information & communication | 2014 |
| Tamasha Group Limited | Other services | 2020 |
| Tamasha Handcross Ltd | Hospitality | 2025 |
| Tamasha Holding Limited | Other services | 2020 |
| Tamasha Restaurant Lindfield Limited | Other services | 2021 |
| Tamerlane Consulting Limited | Professional & scientific | 2016 |
| Tamite Ltd | Information & communication | 2007 |
| Tangerine Interests LLP | | 2017 |
| Tangerine Property (Sussex) Ltd | Real estate | 2016 |
| Tangram Planning Limited | Professional & scientific | 2024 |
| Tanyard Services Limited | Construction | 2008 |
| Tapajos Limited | Other services | 2010 |
| Tasha Shaw Ltd | Professional & scientific | 2023 |
| Taste & Toast Catering & Events Ltd | Hospitality | 2023 |
| Tate Production Ltd | Information & communication | 2015 |
| Tattleton Services Limited | Administrative & support | 2013 |
| Taylor Made Project Management Services Limited | Administrative & support | 2006 |
| Taylor Robinson Financial Services Ltd | Financial services | 2024 |
| Taylor Robinson Lettings Ltd | Real estate | 2008 |
| Taylor ROY LLP | | 2021 |
| Taylored Consultancy Solutions Limited | Professional & scientific | 2014 |
| TCD Consultancy Limited | Professional & scientific | 2021 |
| Tdore Development Ltd | Construction | 2026 |
| Teabrew Limited | Agriculture & fishing | 1981 |
| Team Whales Holdings Ltd | Construction | 2026 |
| Teampoint Limited | Construction | 2009 |
| Teamup Health and Wellbeing Limited | Arts & recreation | 2020 |
| Tebco 2 Ltd | Real estate | 2026 |
| Tebco Ltd | Construction | 2005 |
| Tedxbrighton Limited | Administrative & support | 2019 |
| Teepee TV Limited | Information & communication | 2019 |
| Tekenbord Limited | Other services | 2007 |
| Tekmon UK Limited | Information & communication | 2021 |
| Telenet Ltd | Information & communication | 2004 |
| Templar Property Services Ltd | Construction | 2008 |
| Temple (UK) Limited | Professional & scientific | 2014 |
| Temple Consultancy Services Ltd | Professional & scientific | 2005 |
| Temple Environment Ltd | Professional & scientific | 2004 |
| Temple Planning Ltd | Professional & scientific | 2004 |
| Temple Regeneration Limited | Professional & scientific | 2005 |
| Temple Transport Limited | Professional & scientific | 2005 |
| Tenfold Films Limited | Information & communication | 2021 |
| Tennis Sussex Ltd | Arts & recreation | 2022 |
| Tenterden Consulting Limited | Professional & scientific | 2010 |
| Terroir Conveyancing Limited | Professional & scientific | 2025 |
| Terry Mole Holdings Ltd | Construction | 2020 |
| Tesselate Talent Ltd | Administrative & support | 2026 |
| Tessellate Consult Limited | Professional & scientific | 2026 |
| Test Products International Europe Limited | Manufacturing | 2001 |
| Tetrada Holdings Ltd | Financial services | 2024 |
| TG Logistics Limited | Transport & logistics | 2004 |
| Tgwc Holdings Ltd | Professional & scientific | 2024 |
| Thanu & Kanushi Limited | Health & social care | 2024 |
| That Cleaning Company Limited | Administrative & support | 2009 |
| THE 1895 Club Ltd | Financial services | 2024 |
| THE Affordable Housing Group Limited | Real estate | 2015 |
| THE Air-Britain Trust Limited | Other services | 1968 |
| THE Alliance for Parking Data Standards Limited | Professional & scientific | 2018 |
| THE Ashdown Garage Workshops Limited | Wholesale & retail | 2019 |
| THE Avenue Carshalton Management Company Limited | Households | 2025 |
| THE Barney App Limited | Information & communication | 2024 |
| THE Bay Tree (Sussex) Limited | Hospitality | 2007 |
| THE BE Collective Holding Company Ltd | Financial services | 2025 |
| THE Beauty Nest Sussex Ltd | Other services | 2024 |
| THE Beauty Spot Uckfield Limited | Other services | 2016 |
| THE Best Formula Limited | Professional & scientific | 2020 |
| THE Bluebell Corporation Limited | Administrative & support | 1994 |
| THE Board Support Ltd | Professional & scientific | 2002 |
| THE Book Activist Ltd | Administrative & support | 2016 |
| THE Boondocks Kitchen Ltd | Hospitality | 2021 |
| THE Bridge to Healing Ltd | Health & social care | 2015 |
| THE Buchanan Fletcher Partnership Limited | Professional & scientific | 2025 |
| THE Budd Group Limited | Administrative & support | 2025 |
| THE Castle Inn Hickstead Ltd | Hospitality | 2026 |
| THE Cheyne Charity for Children With Cerebral Palsy | Health & social care | 2008 |
| THE Colour Project Limited | Administrative & support | 2014 |
| THE Communications Consultants Limited | Professional & scientific | 2025 |
| THE Compliance Cloud Limited | Administrative & support | 2010 |
| THE Credit Corporation Limited | Financial services | 2004 |
| THE Digital Beacon Ltd | Information & communication | 2015 |
| THE Dog Adventure Barn Ltd | Arts & recreation | 2024 |
| THE Edge Marketing Solutions Limited | Professional & scientific | 1996 |
| THE Elephant Cuisine Ltd | Hospitality | 2019 |
| THE Elephant Room Limited | Professional & scientific | 2017 |
| THE Energy Alignment Method Limited | Other services | 2021 |
| THE Equity Release Adviser Ltd | Financial services | 2025 |
| THE Event Strategists Ltd | Professional & scientific | 2023 |
| THE Exchange Consultancy Ltd | Professional & scientific | 2026 |
| THE Fallow Meadow Limited | Administrative & support | 2022 |
| THE Fashion Incubator Limited | Manufacturing | 2018 |