| Sovereign Jets Limited | Transport & logistics | 2024 |
| Sovereign Sunseeker London Limited | Transport & logistics | 2025 |
| SOW Sussex Ltd | Extraterritorial | 2016 |
| SP Europe Limited | Administrative & support | 2013 |
| Space Planning Trends Limited | Administrative & support | 2012 |
| Spacelink Commercial Interiors Limited | Other services | 2019 |
| Spaces - Professional Serviced Offices Limited | Real estate | 2023 |
| SPB Plumbing & Heating Ltd | Construction | 2000 |
| Spcr Consulting Limited | Professional & scientific | 2014 |
| Spearman Fitness Ltd | Professional & scientific | 2018 |
| Special Projects (AV) Ltd | Construction | 2020 |
| Spectrum Exhibitions Limited | Manufacturing | 2002 |
| Spectrum TV Studio Build Ltd | Administrative & support | 2020 |
| Speech Therapy Sussex Ltd | Public administration | 2020 |
| Spendwizz Limited | Information & communication | 2025 |
| SPG Business Services Ltd | Professional & scientific | 2018 |
| Spherical Investment Ltd | Construction | 2017 |
| Spinnaker Ventures Ltd | Financial services | 2020 |
| Spitfire Property Improvements Limited | Construction | 2020 |
| Split Bean Food Van Limited | Hospitality | 2023 |
| Spore of Sussex Ltd | Agriculture & fishing | 2024 |
| Sportright Group Ltd | Education | 2024 |
| Sports Performance Shoeing Limited | Agriculture & fishing | 2017 |
| Sports Tours Exchange Management Limited | Administrative & support | 2013 |
| Spot Productions UK Ltd | Professional & scientific | 2013 |
| Sprinkles Pets Ltd | Wholesale & retail | 2021 |
| Squires Farm Developments Ltd | Administrative & support | 2013 |
| SS Digital Creations Ltd | Wholesale & retail | 2025 |
| Ssoull Ltd | Professional & scientific | 2021 |
| ST Albans EYE Care Centre Limited | Wholesale & retail | 2017 |
| ST Anthony Project Management Limited | Professional & scientific | 2007 |
| ST Autos Limited | Wholesale & retail | 2023 |
| ST Giles Place Management Limited | Households | 2022 |
| ST Thomas Recruitment Ltd | Administrative & support | 2022 |
| Stablechief Ltd | Agriculture & fishing | 1999 |
| Stackback Ltd | Real estate | 2017 |
| Staff Safety Training Limited | Education | 2014 |
| Stag Hill Design Limited | Professional & scientific | 2015 |
| Stag Hill Lifestyle Limited | Administrative & support | 2019 |
| Stairbridge SPV Limited | Construction | 2023 |
| Stamford Villa Limited | Construction | 2020 |
| Stanbridge Studios Ltd | Construction | 2015 |
| Stanton Miller Recruitment Limited | Administrative & support | 2013 |
| Star Balti House Limited | Hospitality | 2021 |
| Star Consult Energy Limited | Professional & scientific | 2025 |
| Star Service Group Ltd | Hospitality | 2020 |
| Star Vogue Limited | Hospitality | 2010 |
| STAR17 Enterprise Ltd | Wholesale & retail | 2023 |
| Starflex Storage Solutions UK Limited | Wholesale & retail | 2025 |
| Starkey Procurement & Carbon Solutions Ltd | Professional & scientific | 2025 |
| Starling Aviation Limited | Professional & scientific | 2021 |
| Staxil Limited | Administrative & support | 1975 |
| Steadfast Advisory Services Limited | Financial services | 2001 |
| Steadfast Data Solutions Ltd | Information & communication | 2024 |
| Steadfast Healthcare Ltd | Administrative & support | 2024 |
| Stealth Engineering & Machinery Ltd | Manufacturing | 2015 |
| Steel Circle Ltd | Administrative & support | 2025 |
| Stella's Sparkles Limited | Administrative & support | 2022 |
| Stephen Bell Associates Limited | Other services | 2007 |
| Stephen Cockburn Limited | Other services | 1986 |
| Steringway Ltd | Administrative & support | 2018 |
| Sterling Plumbers Ltd | Construction | 2016 |
| Steve Nicolson Limited | Arts & recreation | 2012 |
| Steven Green Plumbing and Heating Services Limited | Construction | 2011 |
| Stevens P R Services Limited | Construction | 2015 |
| Stewart Cleaning & Building Limited | Administrative & support | 2019 |
| Stewarts Delivery Services Limited | Transport & logistics | 2024 |
| Stil Haven Construction Ltd | Construction | 2021 |
| Stills and Blooms Franchise Ltd | Households | 2024 |
| Stingrae Insights Ltd | Professional & scientific | 2025 |
| Stock Security Ltd | Administrative & support | 2020 |
| Stokeley's Sanctuary Ltd | Real estate | 2024 |
| Stomp the Pedal Ltd | Wholesale & retail | 2020 |
| Stone and Compass Ltd | Professional & scientific | 2025 |
| Stone Jelly Limited | Manufacturing | 2011 |
| Stone Survey Limited | Professional & scientific | 2006 |
| Stonebeach Management Limited | Professional & scientific | 2024 |
| Stonecroft Lettings Limited | Real estate | 2025 |
| Stonefield Systems (Europe) Ltd | Information & communication | 2006 |
| Stonehurst Estates Limited | Construction | 1972 |
| Storage Legends Limited | Other services | 2016 |
| Storey Properties Ltd | Real estate | 2026 |
| STORM12 Ltd | Professional & scientific | 2002 |
| Stormrose Investments Ltd | Professional & scientific | 2023 |
| Strategic Engineering & Energy Asset Management Ltd | Professional & scientific | 2016 |
| Strategic Marcomms Consultancy Limited | Professional & scientific | 2014 |
| Streamsolution Tech UK Ltd | Information & communication | 2022 |
| Strength & Stretch With Craig Limited | Arts & recreation | 2021 |
| Stretton Property Investments Ltd | Construction | 2025 |
| Strevett and Sons Ltd | Construction | 2025 |
| Stripes and Dots Limited | Professional & scientific | 2011 |
| Stuart & Partners Holdings Limited | Financial services | 2022 |
| Stuart & Partners Ltd. | Real estate | 1992 |
| Student Prime Ltd | Real estate | 2019 |
| Studio 10 Fitness Club Ltd | Other services | 2015 |
| Studio Camino Ltd | Information & communication | 2009 |
| Studio Canard Limited | Information & communication | 2016 |
| Studio N Create Limited | Professional & scientific | 2018 |
| Studio Wilkinson Limited | Professional & scientific | 2021 |
| Stumlet Consulting Limited | Financial services | 2005 |