| Spring Meadow Management Company Limited | Households | 2010 |
| Spud HUT Bexhill Ltd | Hospitality | 2025 |
| Squires Irondesigns (Steel Erections) Limited | Other services | 1979 |
| SRC Roofing Limited | Construction | 2026 |
| SRS Property Group UK Ltd | Real estate | 2021 |
| SSW Builders Limited | Construction | 2013 |
| ST Pauls Avenue Property Management LLP | | 2021 |
| Stalley Capital Limited | Financial services | 2026 |
| Stalley Holdings Limited | Financial services | 2025 |
| Stean Properties LLP | | 2023 |
| Stephen Howe & Mandy Rowse Properties Limited | Real estate | 2017 |
| Steven Lenczner Architects Limited | Professional & scientific | 2017 |
| Steyning Avenue Limited | Health & social care | 2018 |
| STG Estate Ltd | Real estate | 2022 |
| STG Property Partnership LLP | | 2022 |
| Stijl Homes Limited | Other services | 2014 |
| Stocchetti Holdings (Fleet) Ltd | Real estate | 2021 |
| Stocchetti Holdings (Investments) Ltd | Financial services | 2026 |
| Stocchetti Holdings Farnborough Ltd | Real estate | 2023 |
| Stocchetti Holdings Ltd | Real estate | 2015 |
| Stokes House Residents Limited | Households | 1989 |
| Stone Court Construction Limited | Construction | 2023 |
| Stormont Management Limited | Real estate | 2020 |
| Stormont Property LLP | | 2017 |
| Strand Meadow Construction Ltd | Construction | 2024 |
| STS Plumbing and Heating Hastings Limited | Construction | 2002 |
| Sturdee Property Investment Ltd | Real estate | 2021 |
| Sturdee Property Management LLP | | 2021 |
| Style Ventures Ltd | Professional & scientific | 2020 |
| Stylecourt Builders Limited | Construction | 2020 |
| Sugarman Homes LLP | | 2016 |
| Sunny Creative Limited | Administrative & support | 2012 |
| Sunny Stores Bexhill Ltd | Hospitality | 2025 |
| Sure Start Property Management LLP | | 2021 |
| Sussex BED Centre (Bexhill) Ltd | Wholesale & retail | 2014 |
| Sussex BED Centre (Distribution) Ltd | Wholesale & retail | 2014 |
| Sussex BED Centre (Hailsham) Ltd | Wholesale & retail | 2014 |
| Sussex BED Centre (Haywards Heath) Ltd | Wholesale & retail | 2014 |
| Sussex BED Centre (Holdings) Ltd | Financial services | 2014 |
| Sussex BED Centre (Newhaven) Ltd | Wholesale & retail | 2014 |
| Sussex BED Centre (Portslade) Ltd | Wholesale & retail | 2014 |
| Sussex BED Centre (Uckfield) Ltd | Wholesale & retail | 2014 |
| Sussex BED Centres (Worthing) Ltd | Wholesale & retail | 2014 |
| Sussex Beds (Ashford) Ltd | Wholesale & retail | 2020 |
| Sussex Beds (Canterbury) Ltd | Wholesale & retail | 2021 |
| Sussex Beds (Tonbridge) Ltd | Wholesale & retail | 2017 |
| Sutton Groundcare Limited | Administrative & support | 2009 |
| Symphony Property Management LLP | | 2024 |
| T a Drilling (Sales) Limited | Wholesale & retail | 2007 |
| T T W Property & Maintenance Limited | Real estate | 2017 |
| T&T Window Consultants Ltd | Professional & scientific | 2023 |
| T2 Spatialwork Limited | Professional & scientific | 2003 |
| TAB Investments LLP | | 2019 |
| TAG Equipment Limited | Wholesale & retail | 2022 |
| Talenteam Holdings Ltd | Information & communication | 2023 |
| Talenteam Investments Ltd | Financial services | 2022 |
| Talenteam Labs Ltd | Financial services | 2024 |
| Talenteam Limited | Information & communication | 2012 |
| Tapp's Plumbing Services Limited | Construction | 2016 |
| Tax & Wealth Protection Service LLP | | 2013 |
| Taylor Made Paving & Groundworks Limited | Construction | 2021 |
| TCR (Sussex) Limited | Construction | 2003 |
| Team Interiors Limited | Construction | 2011 |
| TEN66 Television Limited | Information & communication | 2014 |
| Terra Urbana Investments Limited | Real estate | 2023 |
| Terra Urbana Limited | Real estate | 2019 |
| TFI Legal Limited | Professional & scientific | 2016 |
| That Catering Company Ltd | Hospitality | 2019 |
| THE 8 Kenilworth RD RTM Company Limited | Extraterritorial | 2013 |
| THE Albany Bexhill Ltd | Hospitality | 2018 |
| THE Bespoke Audio Company Limited | Manufacturing | 2013 |
| THE Contractors Accountant Limited | Professional & scientific | 2014 |
| THE Corporate SKI Company Limited | Professional & scientific | 1996 |
| THE ELM Shades Limited | Hospitality | 2012 |
| THE Ideas LAB Brighton Limited | Manufacturing | 2017 |
| THE Knee Foundation | Education | 1991 |
| THE Natural Letting Agency Limited | Real estate | 2024 |
| THE Oak Bakery Limited | Hospitality | 2011 |
| THE Pelican Diner Ltd | Hospitality | 2015 |
| THE Shooting Party Consultants LLP | | 2018 |
| THE Shooting Party Limited | Information & communication | 2012 |
| THE Stour Fish Farm Ltd | Agriculture & fishing | 2019 |
| THE Tanning Bar Limited | Other services | 2022 |
| THE Thirsty Swan Limited | Hospitality | 2024 |
| THE Yard (Brighton) Limited | Real estate | 2017 |
| Thememagic Limited | Real estate | 2000 |
| Thirsty Mushroom Limited | Hospitality | 2012 |
| Thomason Family Holdings Ltd | Real estate | 2017 |
| Thomason Family Partnership LLP | | 2017 |
| Through the Roof Limited | Real estate | 2021 |
| Thurstons Holdings Limited | Financial services | 2024 |
| Tiger Network Solutions Limited | Information & communication | 2005 |
| TIJ Investments Limited | Real estate | 2022 |
| TIM Day & Co. Ltd | Real estate | 2008 |
| Timnow Ltd | Information & communication | 2004 |
| Tiso UK Limited | Public administration | 2017 |
| TM Construction Battle Limited | Construction | 2015 |
| TND Consulting Engineers Limited | Professional & scientific | 2012 |
| TOM MAY Properties Limited | Real estate | 2025 |
| TOM Pollard HIP and Knee Surgery Ltd | Health & social care | 2015 |