| Sunneac Limited | Wholesale & retail | 2018 |
| Sunrise Carpentry Limited | Construction | 2016 |
| Sunview Limited | Households | 2001 |
| Surma Properties Ltd | Real estate | 2024 |
| Sussex Bears CIC | Education | 2019 |
| Sussex Bookkeepers Ltd | Professional & scientific | 2007 |
| Sussex Building & Maintenance Ltd | Administrative & support | 2018 |
| Sussex Cards & Gift Ltd | Wholesale & retail | 2025 |
| Sussex Coaches Ltd | Extraterritorial | 2015 |
| Sussex County Football Association Limited | Arts & recreation | 1999 |
| Sussex Dairy Services Limited | Hospitality | 2018 |
| Sussex EAR WAX Removal Ltd | Health & social care | 2024 |
| Sussex Engineering Car & Commercial Limited | Wholesale & retail | 2016 |
| Sussex Gynaecologist Ltd | Health & social care | 2026 |
| Sussex Partitions Ltd | Construction | 2018 |
| Sussex Peptides Ltd | Professional & scientific | 2025 |
| Sussex Print Limited | Manufacturing | 2021 |
| Sussex Rendering Specialist Ltd | Construction | 2019 |
| Sussex Seagulls Limited | Real estate | 2020 |
| Sussex Stoves and Maintenance Limited | Other services | 2022 |
| Sussex Transport Holdings Limited | Financial services | 2025 |
| Sussex Transport Limited | Transport & logistics | 2002 |
| Sussex Travel & Transport Ltd | Transport & logistics | 2024 |
| Sussex Womens Clinic Limited | Health & social care | 2013 |
| Suteki Ltd | Information & communication | 2026 |
| SWA Property Services Ltd | Construction | 2015 |
| Sweetinburgh & Windsor Ltd | Professional & scientific | 2011 |
| System Ghosts Ltd | Professional & scientific | 2026 |
| T & C Engineering & Maintenance Ltd | Professional & scientific | 2025 |
| T. LE Contracting Ltd | Construction | 2023 |
| TA Media Group Limited | Information & communication | 2024 |
| Taffandy Homes Ltd | Real estate | 2022 |
| Tagus Capital LLP | | 2021 |
| Talentflow Ltd | Professional & scientific | 2025 |
| Tali's Studio Ltd | Arts & recreation | 2016 |
| Tamarind Brighton Limited | Hospitality | 2026 |
| Tamp & Grind (Burgess Hill) Ltd | Hospitality | 2025 |
| Tamp & Grind (Lancing) Ltd | Hospitality | 2023 |
| TAN & LAU Property Limited | Real estate | 2020 |
| TAN Ventures Ltd | Wholesale & retail | 2025 |
| Tara Signs Limited | Manufacturing | 1971 |
| Tarantulabarn Retail Ltd | Wholesale & retail | 2020 |
| Target Rigging Ltd | Manufacturing | 2022 |
| Taylor's Fish 681 Limited | Hospitality | 2024 |
| TBC Valeting Ltd | Wholesale & retail | 2022 |
| Teacup Property Investments Limited | Real estate | 2017 |
| TEC Electrical & Solar Ltd | Construction | 2018 |
| TEC Trade Services Ltd | Wholesale & retail | 2024 |
| Techtesters Holdings Limited | Financial services | 2022 |
| Techtesters Limited | Administrative & support | 2013 |
| Telfords Bistro Ltd | Hospitality | 2023 |
| Telliu Property Ltd | Real estate | 2025 |
| Temco Ltd | Wholesale & retail | 2003 |
| Temperature Services UK Ltd | Construction | 2020 |
| Tensor Health Ltd | Information & communication | 2026 |
| Term Construction Limited | Construction | 2013 |
| Terra Nuova Limited | Professional & scientific | 2014 |
| Tesseract Ltd | Professional & scientific | 2024 |
| TGM Publishing Limited | Information & communication | 2017 |
| THE Airbrush Company Limited | Wholesale & retail | 1992 |
| THE Arts College Limited | Education | 2017 |
| THE Beachside Montessori Nursery Ltd. | Education | 2017 |
| THE Black & White Company Limited | Professional & scientific | 2002 |
| THE Business Creative Limited | Administrative & support | 2010 |
| THE Cabinet Manufacturing Company Ltd | Manufacturing | 2025 |
| THE Campervan Hub Ltd | Wholesale & retail | 2021 |
| THE Clean Company (Sussex) Ltd | Other services | 2017 |
| THE Clubhouse Simulator Lounge Ltd | Arts & recreation | 2026 |
| THE Copper Leaf Heating Company Ltd | Construction | 2025 |
| THE Distinctive Collection Ltd | Professional & scientific | 2021 |
| THE Fighting Tigers Gym Ltd | Arts & recreation | 2011 |
| THE Fold Creative Limited | Professional & scientific | 2019 |
| THE Fold Creative Studio Limited | Professional & scientific | 2024 |
| THE Fold Group Holding Limited | Financial services | 2024 |
| THE Fulfilment Specialists Ltd | Financial services | 2025 |
| THE Hangman Doors Ltd | Construction | 2023 |
| THE Inheritance Group Ltd | Administrative & support | 2023 |
| THE Ironworks Gymnasium Limited | Arts & recreation | 2012 |
| THE Kitchen Cleaning Group Ltd | Administrative & support | 2018 |
| THE Little Hoof Company Ltd | Other services | 2025 |
| THE Luxury COT Company Ltd | Wholesale & retail | 2024 |
| THE MAC Shack Ltd | Hospitality | 2022 |
| THE Mobile Motor Medic Ltd | Professional & scientific | 2025 |
| THE Musketeerium Ltd | Real estate | 2021 |
| THE Patcham Building Company Limited | Construction | 2017 |
| THE Pendragon Project C.I.C. | Education | 2019 |
| THE Physio Suite Ltd | Health & social care | 2012 |
| THE Plant Eater Limited | Administrative & support | 2021 |
| THE Preloved Atelier Ltd | Wholesale & retail | 2023 |
| THE Premier 68 Catering Ltd | Wholesale & retail | 2026 |
| THE Premier 68 Ltd | Hospitality | 2024 |
| THE Premier 680 Ltd | Hospitality | 2026 |
| THE Presbytery Lancing Ltd | Real estate | 2024 |
| THE Real Bamboo Company Limited | Wholesale & retail | 2020 |
| THE Rustic Summerhouse Company Limited | Wholesale & retail | 2008 |
| THE Shippedo Limited | Wholesale & retail | 2024 |
| THE Sussex Cove Gardening Company Ltd | Professional & scientific | 2025 |
| THE UX Coach Ltd | Professional & scientific | 2021 |
| THE Voltabing Company Ltd | Construction | 2019 |
| THE Worthing Journal LLP | | 2010 |