| Runcible Design Ltd | Professional & scientific | 2026 |
| Runqiu Ltd | Hospitality | 2025 |
| Rural Planning Group Limited | Professional & scientific | 2017 |
| Rural Welding Co. Ltd | Manufacturing | 2025 |
| Rushlab Limited | Arts & recreation | 2025 |
| Russell Beck Studio Limited | Manufacturing | 2000 |
| Rutherford Brown Recruitment Ltd | Financial services | 2026 |
| RW Steel Services Ltd | Construction | 2010 |
| Rycombe Consulting Limited | Information & communication | 1998 |
| Rytex Data Services Limited | Information & communication | 1996 |
| S Best Racing Limited | Arts & recreation | 2017 |
| S G Kitchens & Renovations LLP | | 2011 |
| S J Bristow Limited | Manufacturing | 2002 |
| S L Properties Sussex Limited | Real estate | 2009 |
| S L Russell Ltd | Construction | 2024 |
| S.C.I. Products Limited | Construction | 2000 |
| S.G. Southern Properties Limited | Extraterritorial | 2002 |
| Saaba Living Ltd | Wholesale & retail | 2024 |
| Sabara Holdings Ltd | Real estate | 2019 |
| SAH Investments Limited | Administrative & support | 2001 |
| SAI Practices Ltd | Health & social care | 2019 |
| Salamander Treks Limited | Administrative & support | 2007 |
| Sallows Associates Ltd | Professional & scientific | 2015 |
| Sallows Associates Property Ltd | Real estate | 2023 |
| Sally Mortimore Nutrition Ltd | Health & social care | 2017 |
| Salon Advantage Systems Ltd | Information & communication | 2012 |
| SAM Taylor Building Services Ltd | Construction | 2024 |
| Samueljcommerce Ltd | Wholesale & retail | 2026 |
| Samzar CIC | Manufacturing | 2025 |
| Sanditon Hall Ltd | Hospitality | 2021 |
| Sandy RAY Ltd | Wholesale & retail | 2023 |
| Sandycombe Limited | Professional & scientific | 2025 |
| Sandyford Farms Limited | Agriculture & fishing | 2026 |
| SAP & PMI Experts Limited | Information & communication | 2016 |
| Sara Cremer Ltd | Professional & scientific | 2020 |
| Sarah Mcadam Interior Design Limited | Professional & scientific | 2025 |
| Sarah's Steam Emporium Ltd | Wholesale & retail | 2025 |
| Savage Identity Ltd | Wholesale & retail | 2015 |
| Save OUR Soles Limited | Wholesale & retail | 2024 |
| Savill Staging and Styling Limited | Professional & scientific | 2020 |
| Saville Jones Consultants Ltd | Professional & scientific | 2003 |
| Saxondown Farm Estate Management Limited | Real estate | 2022 |
| Saxondown Farm Estates Limited | Real estate | 2016 |
| Saxondown Farm Holdings Limited | Financial services | 2024 |
| Saxondown Farm Limited | Construction | 2016 |
| SB Social UK Ltd | Information & communication | 2023 |
| SBL Arts Limited | Information & communication | 2024 |
| SBS (Lewes) Ltd | Other services | 2017 |
| SC - Data Insight & Analysis Ltd | Information & communication | 2019 |
| Scale Consultancy Ltd | Professional & scientific | 2024 |
| Scallows Ltd | Hospitality | 2020 |
| Scarlett Holdings Limited | Real estate | 2015 |
| SCM Best Practice Ltd | Administrative & support | 2014 |
| Scms London Ltd | Hospitality | 2012 |
| Scott Parker Consultancy Limited | Information & communication | 2012 |
| Scout & Co Ltd | Wholesale & retail | 2013 |
| SDK Woodcrafts Limited | Construction | 1999 |
| SDL Property Maintenance Ltd | Education | 2004 |
| SEA7 Solutions Limited | Financial services | 2024 |
| Seabreeze Lets Limited | Real estate | 2019 |
| Seago Holdings Limited | Professional & scientific | 2008 |
| Seago Yachting Limited | Wholesale & retail | 2002 |
| Seagrove Development Limited | Construction | 2020 |
| Sean Perkins Property and Building Services Ltd | Construction | 2011 |
| Search Properties Limited | Real estate | 2009 |
| Secret Camping Club Limited | Arts & recreation | 2015 |
| Seed Game Ltd | Professional & scientific | 2025 |
| Seedbed Global Ltd | Wholesale & retail | 2024 |
| Seeking OUT Solutions Limited | Professional & scientific | 2021 |
| SEN Ninja Ltd | Information & communication | 2020 |
| Sensara Ltd | Health & social care | 2008 |
| Seren Internet Limited | Information & communication | 2010 |
| SET Theatre Limited | Arts & recreation | 2015 |
| Sewells Solar Limited | Energy | 2015 |
| Sgld Limited | Real estate | 2022 |
| Shad Associates Ltd | Information & communication | 2008 |
| Shapiro Consulting Limited | Professional & scientific | 2002 |
| Shaun Hart Financial Planning Limited | Financial services | 2011 |
| Shaw Farm (Plumpton) Limited | Agriculture & fishing | 1973 |
| Shawbury Consulting Ltd | Administrative & support | 2022 |
| Shearway Park Development Ltd | Construction | 2024 |
| Shedunnit Productions Limited | Arts & recreation | 2018 |
| Shelf Space Limited | Wholesale & retail | 2003 |
| Shell-Clad Ltd | Administrative & support | 2000 |
| Shield Build Ltd | Construction | 2014 |
| Shirley Properties Limited | Real estate | 1936 |
| Shore Place Ltd | Agriculture & fishing | 2020 |
| Shorebrook Partners Ltd | Administrative & support | 2020 |
| Short Story Limited | Information & communication | 2020 |
| Shovel Brothers Golf Brighton Ltd | Hospitality | 2026 |
| Shovel Brothers Golf Ltd | Hospitality | 2026 |
| Shrc Consulting Limited | Information & communication | 2025 |
| Sideline Clothing Ltd | Arts & recreation | 2012 |
| Sideline Design Studio Ltd | Real estate | 2023 |
| Sidesky Property Management Limited | Households | 1990 |
| Sierra Bravo Aviation Limited | Administrative & support | 2012 |
| Sierra Victor Advisory Limited | Professional & scientific | 2025 |
| Sifelle Limited | Construction | 2023 |
| Sight and Sound Services Limited | Information & communication | 2022 |
| Signature KH Limited | Real estate | 2024 |