| Southwestern Hangar LLP | | 2010 |
| Sovereign Endoscopy LLP | | 2011 |
| Sovereign Operations LLP | | 2012 |
| Sovereign Surgical LLP | | 2011 |
| Sovereign Surgical Services Ltd | Manufacturing | 2026 |
| Space for Breath Ltd | Health & social care | 2022 |
| Sparkes Property Development Limited | Real estate | 2003 |
| Spartan Brickwork & Construction Ltd | Construction | 2023 |
| Spiral Jewellery Ltd | Wholesale & retail | 2006 |
| Spotless Solar Ltd | Administrative & support | 2022 |
| Spring Global Trading Limited | Financial services | 2023 |
| Squall III Ltd | Real estate | 2015 |
| ST. Bernard's Court Tenants' Association Limited | Households | 1969 |
| Star Garagee Ltd | Wholesale & retail | 2025 |
| Stardust Travel Ltd | Administrative & support | 2021 |
| Stay by the Sea Ltd | Hospitality | 2014 |
| Steely Glint Limited | Manufacturing | 2017 |
| Stet Copywriting Ltd | Administrative & support | 2013 |
| Steve Garwood Limited | Real estate | 2014 |
| Sticky Fingers Worthing Limited | Education | 2014 |
| Stirlingworks Limited | Professional & scientific | 2010 |
| Stirred Health Limited | Professional & scientific | 2021 |
| STL Communications Limited | Information & communication | 1996 |
| Stoneturners Ltd | Information & communication | 2025 |
| Store by Sea Ltd | Wholesale & retail | 2025 |
| Stores on the Web Limited | Wholesale & retail | 1996 |
| Stormwatch Security Limited | Administrative & support | 2025 |
| Strive in the Way of Allah Limited | Other services | 2014 |
| Stuart Radley Associates Limited | Real estate | 2014 |
| Studio THREE19 Reformer Pilates Ltd | Arts & recreation | 2025 |
| Studio Turini Ltd | Information & communication | 2026 |
| SUB7 Collection Ltd | Professional & scientific | 2023 |
| Sugar Free Property Limited | Real estate | 2021 |
| Summer Enterprise UK Ltd | Wholesale & retail | 2026 |
| Sunscript Ltd | Professional & scientific | 2024 |
| Sussex Arts Club Limited | Hospitality | 1994 |
| Sussex Court Limited | Real estate | 1993 |
| Sussex Dyslexia Ltd | Education | 2025 |
| Sussex Festival of Dance and Song | Arts & recreation | 2010 |
| Sussex Floors Limited | Construction | 1969 |
| Sussex Food Markets Limited | Wholesale & retail | 2023 |
| Sussex Garden Rooms Limited | Construction | 2017 |
| Sussex Glazing Properties Limited | Real estate | 2020 |
| Sussex Glazing Services Limited | Construction | 2013 |
| Sussex Homewares Ltd | Wholesale & retail | 2019 |
| Sussex Joinery Ltd | Manufacturing | 2007 |
| Sussex Lawn & Weed Care Limited | Administrative & support | 2013 |
| Sussex Lets Limited | Real estate | 2024 |
| Sussex Loft Construction Limited | Construction | 2016 |
| Sussex Precision Engineering Ltd | Manufacturing | 2013 |
| Sussex Roofing and Building Services Limited | Construction | 2013 |
| Sussex Security Services Close Protection Ltd | Administrative & support | 2023 |
| Sussex Security Services Ltd | Administrative & support | 2021 |
| Sussex Select Soccer LLP | | 2009 |
| Sussex Timber Company Limited | Other services | 2016 |
| Sussex Vehicles Finance Limited | Financial services | 2003 |
| Sussex Wharf Estate Residents Association Limited | Households | 2005 |
| Sussex Yacht Club,Limited | Arts & recreation | 1926 |
| SVX Group Limited | Financial services | 2025 |
| Swarmall Limited | Real estate | 2019 |
| Swat Marketing Ltd | Arts & recreation | 2006 |
| SWC Cloud Services Limited | Administrative & support | 1990 |
| Swcomms - Energy Limited | Energy | 2018 |
| Swim Teach Train Ltd | Extraterritorial | 2014 |
| SYC Operations Ltd | Hospitality | 2014 |
| Sydney Evans Ltd | Wholesale & retail | 2023 |
| Synertial Technologies Ltd | Other services | 2018 |
| Synertial UK Ltd | Information & communication | 2013 |
| T J Donegan Ltd | Professional & scientific | 2019 |
| T-Plan Limited | Information & communication | 1999 |
| T.E.A. Consultancy Ltd | Professional & scientific | 2010 |
| Tactile Tools Ltd | Manufacturing | 2019 |
| Take UP Space Ltd | Professional & scientific | 2019 |
| Talty James Ltd | Administrative & support | 2024 |
| Tamarind Events Ltd | Administrative & support | 2025 |
| Tanks and Targets Ltd | Arts & recreation | 2021 |
| Tape Industries Limited | Professional & scientific | 2025 |
| Tara Court Residents Limited | Households | 2018 |
| Target Technical Consulting Ltd | Professional & scientific | 2017 |
| Tarring Road Freehold Limited | Households | 2024 |
| Tasty Shoreham 2025 Ltd | Hospitality | 2025 |
| Taurus Clearer Communication Limited | Information & communication | 1985 |
| Taylor Group Ltd | Financial services | 2025 |
| Tech Gorillas Ltd | Information & communication | 2017 |
| Tech Help IT Limited | Information & communication | 2026 |
| Temple Publishing Limited | Arts & recreation | 2008 |
| TEN ST Michael's Place (Brighton) Limited | Households | 1994 |
| Terracove Limited | Professional & scientific | 2025 |
| Testing World.Net Limited | Other services | 2002 |
| Tfortransition CIC | Education | 2025 |
| TFW Properties Limited | Real estate | 2020 |
| THE 2 King's Gardens Management Company Limited | Real estate | 2001 |
| THE Adele Experience UK Ltd | Arts & recreation | 2024 |
| THE Assessment Professionals Limited | Professional & scientific | 2014 |
| THE Authentic Leadership Coach Ltd | Professional & scientific | 2023 |
| THE Barefaced Edit Ltd | Other services | 2026 |
| THE Beneficial Raffle Ltd | Extraterritorial | 2024 |
| THE Black and Minority Ethnic Young Peoples' Project | Health & social care | 2009 |
| THE Bright Space Company (Sussex) Ltd | Administrative & support | 2022 |
| THE Brighton and Hove Group Limited | Construction | 2024 |