| Tbph Limited | Other services | 2012 |
| TDM Solutions Limited | Information & communication | 2006 |
| TDR Dental Ltd | Professional & scientific | 2019 |
| Teal Stripe Ltd | Construction | 2018 |
| Techlogic Software Solutions Limited | Information & communication | 2017 |
| Teddy Treats Childrens Charity Limited | Other services | 2014 |
| Tefl Lemon Ltd | Information & communication | 2019 |
| TEO Consultancy Ltd | Construction | 2025 |
| Tgnp Limited | Information & communication | 2015 |
| Thatcher Place Estate Company Limited | Real estate | 1999 |
| THE 203 Group Limited | Professional & scientific | 2023 |
| THE Before I DIE Network Ltd | Other services | 2014 |
| THE Blue Room (Seaford) Limited | Other services | 2025 |
| THE Brighton Building Co Ltd | Construction | 2023 |
| THE Builders Club Developments Ltd | Construction | 2025 |
| THE Builders Club Ltd | Construction | 2009 |
| THE Builders Club Property Services Ltd | Real estate | 2021 |
| THE Community Wellbeing Initiative CIC | Professional & scientific | 2025 |
| THE Connection Matrix Limited | Administrative & support | 2009 |
| THE Content Community Limited | Professional & scientific | 2015 |
| THE Covers Freehold Limited | Real estate | 1996 |
| THE Cupboard Door Company Limited | Manufacturing | 2003 |
| THE Eastbourne Antiques Centre Limited | Wholesale & retail | 2026 |
| THE Front Room (Seaford) Limited | Hospitality | 2013 |
| THE Grays Estate Management Ltd | Real estate | 2018 |
| THE Green Runners CIC | Education | 2023 |
| THE Griffin Community Trust | Health & social care | 1991 |
| THE Hair Company Lewes Limited | Other services | 2014 |
| THE Hikers Rest Ltd | Hospitality | 2022 |
| THE Hormone Centre Limited | Health & social care | 2022 |
| THE Howitt Group Ltd | Financial services | 2024 |
| THE Kayak Coach Limited | Administrative & support | 2015 |
| THE Longfellow (India) Company Limited | Other services | 2011 |
| THE Lounge About Company Limited | Wholesale & retail | 2002 |
| THE Meadows (Cuckfield) Management Company Limited | Households | 2010 |
| THE Mind Clinic Limited | Health & social care | 2014 |
| THE Old Town Forge C.I.C. | Education | 2026 |
| THE Patchwork Cat Limited | Hospitality | 2017 |
| THE People's Choice Ltd | Health & social care | 2012 |
| THE Phoenix Mews Property Management Company Limited | Households | 2007 |
| THE Portal Collective Ltd | Administrative & support | 2022 |
| THE Redeemed Christian Church of GOD, Kingdom Life Assembly, Seahaven | Other services | 2025 |
| THE Risings RTM Company Limited | Households | 2019 |
| THE Sabden Multi Academy Trust | Education | 2015 |
| THE Salted Spine Bookstore Ltd | Manufacturing | 2026 |
| THE Sanding & Sealing Company Ltd | Construction | 2013 |
| THE Sloan Clinics Ltd | Health & social care | 2018 |
| THE Social Varsity Club Limited | Arts & recreation | 2023 |
| THE Spark Knight Ltd | Construction | 2025 |
| THE Sussex Sign Company Limited | Manufacturing | 2003 |
| THE View Seaford Ltd | Hospitality | 2023 |
| THE Virgo Organisation Ltd. | Information & communication | 2024 |
| THE Wellbeing Room Collective Ltd | Other services | 2025 |
| THE Woodworking Branch Ltd | Manufacturing | 2017 |
| THE6TH.STUDIO Ltd | Information & communication | 2022 |
| THEPOWEROF4 Consulting Ltd | Professional & scientific | 2023 |
| This IS Mabel Ltd | Wholesale & retail | 2025 |
| This Weeks Best Sellers Ltd | Wholesale & retail | 2022 |
| Thomas Auster Accounting Ltd | Professional & scientific | 2018 |
| Throttle and Torque Ltd | Wholesale & retail | 2025 |
| Thumbellen@ Limited | Professional & scientific | 2025 |
| Thyme for Food & Friends Ltd | Professional & scientific | 2013 |
| Ticktockrobot Limited | Arts & recreation | 2010 |
| Tide Mills Management Company Limited | Real estate | 2015 |
| Tidemill Ltd | Information & communication | 2026 |
| Tidepool Hospitality Ltd | Information & communication | 2026 |
| Tiger Feet Solutions Limited | Professional & scientific | 2013 |
| Tile Centre Warehouse Ltd | Wholesale & retail | 2018 |
| TIP Top Construction (Sussex) Ltd | Construction | 2020 |
| Tl&K Property Ltd | Real estate | 2023 |
| Tobbs Ltd | Manufacturing | 2025 |
| TOM Hall Electrical Ltd | Construction | 2026 |
| Toploaded Collectables Ltd | Wholesale & retail | 2025 |
| Toro Renovations Ltd | Construction | 2016 |
| Torque&Gloss Ltd | Administrative & support | 2026 |
| Total Books Seaford Ltd | Professional & scientific | 2014 |
| Total Mortgages Ltd | Financial services | 2019 |
| Totally British Limited | Extraterritorial | 2020 |
| Trans TEL Europe Ltd | Construction | 1998 |
| Transtel Engineering Ltd | Information & communication | 1996 |
| Tredellian Publishing Limited | Information & communication | 2023 |
| Tree Wizard Sussex Ltd | Administrative & support | 2021 |
| Trench Tech Ltd | Administrative & support | 2025 |
| Trendy Limited | Real estate | 2003 |
| TRH Brickwork Limited | Construction | 2018 |
| Trixstar Ltd | Arts & recreation | 2025 |
| TRK Invest Ltd | Real estate | 2022 |
| Truck Services of Sussex Limited | Wholesale & retail | 2002 |
| Trusted Finance Limited | Professional & scientific | 2024 |
| Tudor Manor Management Limited | Extraterritorial | 2010 |
| Tuition Trips Ltd | Administrative & support | 2023 |
| Tuskmore Limited | Real estate | 2007 |
| Tutorwiz Ltd | Education | 2018 |
| TVC Films Ltd. | Information & communication | 2001 |
| TW Libra Ltd | Professional & scientific | 2025 |
| Twin Creations Ltd | Information & communication | 2014 |
| Uckfield Logistics Ltd | Transport & logistics | 2024 |
| UK Bamboo Supplies Limited | Wholesale & retail | 2004 |
| Uprise Rental Ltd | Real estate | 2026 |
| Uyen Ngoc Ltd | Other services | 2021 |