| Synapsys Solutions Trustees Limited | Administrative & support | 2022 |
| Synergy Business Management Limited | Professional & scientific | 2003 |
| Synergy Direct Marketing Limited | Administrative & support | 2004 |
| Synergy Group Sussex Limited | Administrative & support | 2000 |
| Syntec Resources Limited | Professional & scientific | 2003 |
| Syon House (Management) Ltd. | Households | 2003 |
| T & G L Limited | Construction | 2007 |
| T K E Mechanical Services Limited | Construction | 2017 |
| T Peacock Bespoke Limited | Construction | 2025 |
| T.L. Carr (Electrical Supplies) Limited | Wholesale & retail | 1975 |
| T.R. Design Associates Limited | Professional & scientific | 1990 |
| T8 Hundred Ltd | Administrative & support | 2025 |
| TAG Building and Contractors Ltd | Construction | 2023 |
| Tamarind Hayman Ltd | Wholesale & retail | 1999 |
| Tangerine Anvil Limited | Professional & scientific | 2002 |
| Tarlingsil Limited | Professional & scientific | 2022 |
| TAS Building Contractors Limited | Construction | 2009 |
| Tatty Bojangles Limited | Manufacturing | 2022 |
| Tax Adept Accountants Limited | Extraterritorial | 2017 |
| Taza Indian Cuisine Ltd | Hospitality | 2018 |
| TBS Electrical Ltd | Construction | 2016 |
| TC Contractors (Sussex) Limited | Construction | 2013 |
| TCR Removals Ltd | Transport & logistics | 2014 |
| Tea Thyme Limited | Hospitality | 2020 |
| Tech-Takeback Ltd | Water & waste | 2017 |
| Technology Repair Centre Limited | Information & communication | 2024 |
| Teichmann Limited | Other services | 2018 |
| Teknol House Ltd | Real estate | 2000 |
| Tenfold Finance Ltd | Professional & scientific | 2026 |
| Terren Limited | Professional & scientific | 2024 |
| Thackery & William Limited | Construction | 2026 |
| Thames Hedging Ltd | Administrative & support | 2016 |
| Thameside Property Services Ltd | Construction | 2026 |
| THE Alliance Agents Ltd | Professional & scientific | 2023 |
| THE Bccma Limited | Education | 2022 |
| THE Beauty Garden Ltd | Other services | 2022 |
| THE Brewers Arms Limited | Hospitality | 2014 |
| THE Cardinall's Musick Limited | Arts & recreation | 1997 |
| THE Chevron Shop Limited | Extraterritorial | 2006 |
| THE Commercial Cleaning Group Limited | Administrative & support | 2021 |
| THE Cycling Dutchman Ltd | Wholesale & retail | 2021 |
| THE Disabilities Trust | Health & social care | 1989 |
| THE Donut Club Ltd | Manufacturing | 2024 |
| THE Downland Club (2022) Limited | Real estate | 2007 |
| THE Dream Real Company Ltd | Wholesale & retail | 2018 |
| THE East Street Watch Company Limited | Wholesale & retail | 2021 |
| THE EGY Collective Limited | Professional & scientific | 2024 |
| THE Employer Brand Space Ltd | Professional & scientific | 2024 |
| THE Extinguisher Trading Company Ltd | Administrative & support | 2008 |
| THE Forge (Ringmer) Management Limited | Households | 2005 |
| THE Gift and Gadget Store Limited | Wholesale & retail | 2017 |
| THE Grayling Group Ltd | Information & communication | 2025 |
| THE Handmade & Hire Company Limited | Administrative & support | 2023 |
| THE Hayward Partnership Ltd | Information & communication | 2014 |
| THE Hearing and Mobility Store Limited | Wholesale & retail | 2009 |
| THE Heating Group Ltd | Construction | 2019 |
| THE Honour Board Company Limited | Manufacturing | 2025 |
| THE Journey Coaching and Mentoring Company Limited | Health & social care | 2026 |
| THE Kiln Brewery Ltd | Manufacturing | 2014 |
| THE King's Church Mid-Sussex | Other services | 2005 |
| THE Mercantile Adventurers Limited | Wholesale & retail | 2025 |
| THE Old Grain Store Management Co Ltd | Administrative & support | 2017 |
| THE People Magic Company Ltd | Administrative & support | 2019 |
| THE Performance Blueprint Ltd | Other services | 2025 |
| THE Permanent Makeup Training Academy Ltd | Education | 2012 |
| THE Quadra Foods Ltd | Hospitality | 2025 |
| THE Queensland Group Ltd | Construction | 2020 |
| THE School Base Ltd | Education | 2025 |
| THE Sneaker GUY Ltd | Wholesale & retail | 2020 |
| THE Snug Beauty & Aesthetics Ltd | Other services | 2022 |
| THE Spicy PIE Company Ltd | Manufacturing | 2025 |
| THE Suncare Shop Limited | Wholesale & retail | 2013 |
| THE Sussex Collection Limited | Manufacturing | 2025 |
| THE Traditional Family Funeral Company Limited | Extraterritorial | 2009 |
| THE Travel Visa Company Limited | Administrative & support | 2009 |
| THE Tyre Rack Ltd | Wholesale & retail | 2024 |
| THE Under Water Lighting Company Limited | Administrative & support | 2022 |
| THE University of Canterbury NZ Trust | Education | 2005 |
| THE Village Bistro Limited | Hospitality | 2005 |
| THE Water Business Limited | Construction | 2010 |
| THE West Trees Management Company Limited | Households | 2022 |
| THE Works Plumbing & Heating Ltd | Construction | 2015 |
| THE Wrentham House Management Company Limited | Administrative & support | 1990 |
| THEATRES4U Ltd | Health & social care | 2014 |
| Thermo Aire Ltd | Construction | 2026 |
| Thermoplastics UK Limited | Manufacturing | 2020 |
| Third MAN Records London Limited | Wholesale & retail | 2020 |
| Thirteenth Floor Properties Ltd | Real estate | 2024 |
| Thomas & James Limited | Real estate | 2024 |
| Thompson Plumbing and Heating Limited | Construction | 2014 |
| Thorne’S Catering Limited | Hospitality | 2022 |
| Thorntree Civil Engineering Limited | Professional & scientific | 2026 |
| Thorsten Van Elten Limited | Wholesale & retail | 2004 |
| Three Leaves Consulting Ltd | Professional & scientific | 2025 |
| Timber Mill Flats Management Co. Limited | Households | 1982 |
| Timbergrove Construction Limited | Construction | 2011 |
| Tiny Bars Ltd | Hospitality | 2026 |
| Titan Plumbing & Heating Ltd | Construction | 2020 |
| Tivimi Ltd | Financial services | 2016 |
| Tivimi Studio Ltd | Wholesale & retail | 2025 |