| Steve Richards HR Ltd | Administrative & support | 2014 |
| Stevens Property Group Limited | Professional & scientific | 2021 |
| Stickerbomb Ltd | Wholesale & retail | 2013 |
| Stonepound Ridge Residents Company Limited | Households | 2007 |
| Stonie’S Kitchen Limited | Hospitality | 2024 |
| Storycommons CIC | Education | 2023 |
| Street Surveyors Limited | Professional & scientific | 2019 |
| Strictly Health Ltd | Health & social care | 2015 |
| Strong Advertising Ltd | Professional & scientific | 2014 |
| Strong Tower Production Limited | Information & communication | 2018 |
| Stronghold Supplies Ltd | Wholesale & retail | 2023 |
| Stuart Halliwell Consulting Ltd | Professional & scientific | 2023 |
| Studio AE Limited | Professional & scientific | 2024 |
| Studio at NO.6 Ltd | Arts & recreation | 2022 |
| Studio IO Ltd | Arts & recreation | 2019 |
| Studio Monomania Ltd | Information & communication | 2019 |
| Studio Skin UK Limited | Other services | 2024 |
| Sugar Cane Productions Limited | Information & communication | 2014 |
| Sumware LLP | | 2019 |
| Sunam Tandoori (UK) Ltd | Hospitality | 2012 |
| Sunleigh Court Management Co. NO. 2 Ltd | Administrative & support | 2014 |
| Sunshine Bars Limited | Hospitality | 2012 |
| Suntrap Media Ltd | Information & communication | 2010 |
| Supa Vision Systems Ltd | Information & communication | 2008 |
| Super Motor Homes Limited | Administrative & support | 2021 |
| Superconnected Limited | Administrative & support | 2017 |
| Supplements by Design Limited | Professional & scientific | 2025 |
| Surgery House Dental Practice Limited | Health & social care | 2012 |
| Sussex Assemblies Limited | Manufacturing | 2005 |
| Sussex Carpentry Ltd | Manufacturing | 2020 |
| Sussex Central Stores Ltd | Wholesale & retail | 2025 |
| Sussex Chinese Restaurants Limited | Hospitality | 2017 |
| Sussex Country Holidays (Eastbourne) Ltd | Hospitality | 2020 |
| Sussex Country Holidays Ltd | Hospitality | 2010 |
| Sussex Electric Vehicles Ltd | Wholesale & retail | 2020 |
| Sussex Grill Project Limited | Hospitality | 2024 |
| Sussex Homecare (MID Sussex) Limited | Health & social care | 2014 |
| Sussex House (Hurstpierpoint) Management Company Ltd | Households | 2018 |
| Sussex Lantern | Education | 2002 |
| Sussex Living Limited | Manufacturing | 2003 |
| Sussex Motor Finance Limited | Financial services | 2012 |
| Sussex Oak Framed Buildings Ltd | Manufacturing | 2017 |
| Sussex Oak Frames Ltd | Manufacturing | 2017 |
| Sussex Oak Framing Ltd | Extraterritorial | 2017 |
| Sussex Piscatorial Society Ltd | Arts & recreation | 2012 |
| Sussex Property Rentals Ltd | Real estate | 2016 |
| Sussex Retro and Classic Cars Limited | Wholesale & retail | 2011 |
| Sussex Stoneworks Ltd | Construction | 2017 |
| Sussex Van Centre Limited | Wholesale & retail | 2016 |
| SVP Jewellery Ltd | Wholesale & retail | 2014 |
| SW1 Investments Limited | Households | 2020 |
| Sweetlands Management Company (Keymer) Limited | Households | 1987 |
| Switch to Wood Limited | Manufacturing | 1999 |
| Sydney Productions Ltd | Wholesale & retail | 2009 |
| T G Hamilton Construction Limited | Construction | 2012 |
| TAB Right Ltd | Information & communication | 2020 |
| Tammy Noel Consulting Ltd | Professional & scientific | 2026 |
| Tamp the Grind Ltd | Hospitality | 2020 |
| Target Sales Limited | Wholesale & retail | 2011 |
| Tattenham Corner Trading Ltd | Construction | 2022 |
| Taylor Bathrooms Ltd | Construction | 2026 |
| Taylor Stunts Ltd | Arts & recreation | 2015 |
| TBR Legal Consulting Limited | Professional & scientific | 2024 |
| TBS Property Investments Ltd | Real estate | 2024 |
| TBS Property Rentals Ltd | Real estate | 2025 |
| TC Property Enterprises Ltd | Real estate | 2017 |
| Teise Advisory Ltd | Professional & scientific | 2025 |
| Temcom Limited | Information & communication | 2021 |
| Temple Studios (Brighton) Ltd | Information & communication | 2026 |
| Tennis Tots Ltd | Information & communication | 2024 |
| TEQ Consulting Ltd | Information & communication | 2026 |
| Teranga Land Ltd | Real estate | 2015 |
| Tevah Spaces Ltd | Real estate | 2025 |
| Tglr Ltd | Other services | 2023 |
| That Good Creative Ltd | Professional & scientific | 2022 |
| Thatched Holdings Ltd | Hospitality | 2024 |
| THE 95 Club Limited | Agriculture & fishing | 2024 |
| THE Bambino Club Cafe Ltd | Hospitality | 2026 |
| THE Beacons Freehold Company Limited | Households | 2016 |
| THE Birchmead Partnership LLP | | 2009 |
| THE Boilermaker London Limited | Hospitality | 2023 |
| THE Brangwyn Meadow Company Ltd | Households | 2022 |
| THE Brighton Creamery LLP | | 2010 |
| THE Caristocrat Brighton Ltd | Wholesale & retail | 2019 |
| THE Chocolate Emporium Limited | Wholesale & retail | 2017 |
| THE Confidence Clinic by Evie Limited | Other services | 2025 |
| THE Consult Company Network Ltd | Administrative & support | 2023 |
| THE Cruise Line Limited | Administrative & support | 1992 |
| THE Defector Film Limited | Information & communication | 2016 |
| THE Durand Partnership LLP | | 2024 |
| THE Friends of Ditchling | Real estate | 2006 |
| THE Garden Gang at the Macs Farm Community Interest Company | Education | 2025 |
| THE GEE Dog Ltd | Hospitality | 2023 |
| THE Genistas (Hassocks) Limited | Real estate | 2005 |
| THE Implementation Company Limited | Administrative & support | 2005 |
| THE Installation Team Ltd | Construction | 2022 |
| THE Landsculptors Group Limited | Administrative & support | 2025 |
| THE Little Woodshop Limited | Manufacturing | 2023 |
| THE Location Store Limited | Information & communication | 2011 |
| THE London Butterfly Gardens Ltd | Arts & recreation | 2024 |