| Seasons Holiday Properties Limited | Real estate | 2011 |
| Seasons Hotels Limited | Hospitality | 2008 |
| Seasons Title (Ramses) Limited | Professional & scientific | 2012 |
| Second Street Ltd | Wholesale & retail | 2022 |
| Securetech Limited | Professional & scientific | 2008 |
| Seely Developments Limited | Real estate | 2012 |
| Seer Recruitment Limited | Administrative & support | 2019 |
| SEF Landscaping Ltd | Construction | 2024 |
| Select Motor Sales Ltd | Wholesale & retail | 2018 |
| Sensory for ALL Limited | Arts & recreation | 2017 |
| Seren Print Services Limited | Manufacturing | 2013 |
| Setable Limited | Administrative & support | 2024 |
| Seven FM Ltd | Construction | 2026 |
| Seven Shores the Label Ltd | Wholesale & retail | 2019 |
| Seventh Sense Productions Ltd | Information & communication | 2026 |
| Severus Limited | Other services | 2012 |
| SFP Investments Limited | Construction | 1995 |
| SG Tbdc Holdings Ltd | Hospitality | 2020 |
| SG Truck Ltd | Hospitality | 2021 |
| SHA Hub Hire Limited | Professional & scientific | 2024 |
| Shaffer Sheikh Limited | Real estate | 2018 |
| Shah Education Ltd | Education | 2023 |
| Shakester Cakes Ltd | Professional & scientific | 2026 |
| Shane Wheeler Wealth Management Limited | Financial services | 2010 |
| Shared Walls Limited | Wholesale & retail | 2025 |
| Sharksfin Holdings Limited | Professional & scientific | 1997 |
| Sharp Travel Agent Ltd | Hospitality | 2025 |
| Sharps Associates Limited | Financial services | 2011 |
| Shaw Agencies Ltd | Wholesale & retail | 2016 |
| SHE Compliancy Limited | Professional & scientific | 2014 |
| She's Electric (Billericay) Limited | Energy | 2011 |
| Shebaz Solutions Limited | Other services | 2024 |
| Shecompliancy Consultancy & Training Limited | Professional & scientific | 2023 |
| Shelby Partnerships Limited | Construction | 2016 |
| Shellac Nails and Spa Ltd | Other services | 2026 |
| Shenfield Cars Limited | Transport & logistics | 2001 |
| Shenfield Consultancy Ltd | Professional & scientific | 2010 |
| Shenfield Design and Build Ltd | Real estate | 2024 |
| Shenfield Inflatables Ltd | Administrative & support | 2023 |
| Shenfield Taxis Limited | Extraterritorial | 2002 |
| Shepherds TYE Limited | Other services | 2018 |
| Shetech Limited | Construction | 2023 |
| Shiori Takahashi Limited | Other services | 2024 |
| Shipright of Sibson Limited | Transport & logistics | 2013 |
| Shivani Rose Homes Ltd | Real estate | 2024 |
| SHJ Property Ltd | Real estate | 2021 |
| Shoebox Digital Limited | Professional & scientific | 2012 |
| Shoenaghmackay-Leaf Limited | Public administration | 2024 |
| Shorty's Barber Shop Limited | Other services | 2015 |
| Shot Recovery Ltd | Wholesale & retail | 2022 |
| Shott Limited | Public administration | 2022 |
| Showdown Security Ltd | Administrative & support | 2024 |
| SHS Hire Limited | Other services | 2021 |
| Shwings East Ltd | Hospitality | 2022 |
| Shyam & Shubh Limited | Wholesale & retail | 2018 |
| Side Dish Creative Limited | Professional & scientific | 2025 |
| Sierra SIX Consulting Ltd | Professional & scientific | 2024 |
| Sierra SIX Media Limited | Professional & scientific | 2017 |
| SIG Consultants Ltd | Public administration | 2023 |
| Signal Security Limited | Construction | 2001 |
| Signature Car Group Ltd | Wholesale & retail | 2022 |
| Siibello Ltd | Wholesale & retail | 2023 |
| Silc Holdings Ltd | Construction | 2016 |
| Silk Lounge Retail Limited | Other services | 2024 |
| Silk Spraying Solutions Limited | Construction | 2026 |
| Silver Heron Construction Limited | Construction | 2015 |
| Silver Heron Developments Limited | Construction | 2001 |
| Silverland Developments Ltd | Construction | 2014 |
| Silverlands Property Limited | Real estate | 2022 |
| Silverline Clearances Ltd | Transport & logistics | 2021 |
| Silverminute Holdings Limited | Administrative & support | 2010 |
| Silvertongued Limited | Arts & recreation | 2008 |
| Simbiotik Limited | Professional & scientific | 2008 |
| Simon Lewis Comms Limited | Professional & scientific | 2017 |
| Simon Mcgregor IFA Limited | Financial services | 2008 |
| Simpladapt Ltd | Information & communication | 2004 |
| Simply Cladding Limited | Manufacturing | 2024 |
| Simply Metals Limited | Manufacturing | 2024 |
| Simply Plastics Limited | Manufacturing | 2013 |
| Simply Tasha Limited | Information & communication | 2022 |
| Simply Trophies Limited | Manufacturing | 2024 |
| Simpson Mechanical Repairs Limited | Wholesale & retail | 2003 |
| Sims Sprinklers Limited | Public administration | 2026 |
| Sinatra Holdings Ltd | Financial services | 2025 |
| Sinatra Marketing Group Ltd | Manufacturing | 2017 |
| Sinbyte Limited | Information & communication | 2024 |
| Sincordia Limited | Information & communication | 2003 |
| Sirius Property Finance Group Limited | Financial services | 2016 |
| Sitknow Ltd | Transport & logistics | 2019 |
| SJ & Sons Autobody Repairs Essex Ltd | Wholesale & retail | 2023 |
| SJ Clarricoates Limited | Professional & scientific | 2015 |
| SJ Grab Hire Ltd | Water & waste | 2023 |
| SJ Hunt Property Holdings Ltd | Real estate | 2025 |
| SJK (E & M) Site Services Limited | Construction | 2014 |
| SJP Building Services Limited | Construction | 2012 |
| SJP Railway Engineering Limited | Construction | 2013 |
| SJS Opco | Education | 2022 |
| SJT Capital Ltd | Financial services | 2026 |
| Skaret Studio Ltd | Professional & scientific | 2026 |
| Skariaholdings Ltd | Wholesale & retail | 2025 |