| Sarah Styles Florist (Hungerford) Ltd | Wholesale & retail | 2018 |
| Sarah Styles Interiors Ltd | Wholesale & retail | 2018 |
| Sargant Solutions Limited | Extraterritorial | 2019 |
| SB Print Solutions Limited | Professional & scientific | 2022 |
| Scampton Holdings Limited | Real estate | 2020 |
| Scootify Limited | Wholesale & retail | 2022 |
| Scribbled Ltd | Information & communication | 2025 |
| SD Bloodstock Limited | Other services | 2022 |
| SD General Builders Limited | Construction | 2019 |
| Seawell Automatic Controls Limited | Manufacturing | 2005 |
| Sebastian MAW Transport Consultants Ltd | Transport & logistics | 2015 |
| Secundo 2015 Limited | Wholesale & retail | 2015 |
| Security London Limited | Administrative & support | 2016 |
| Seiquelle Innovation Limited | Administrative & support | 2008 |
| Selene Bullion Ltd | Wholesale & retail | 2025 |
| Sell More Tyres Dotcom Ltd | Manufacturing | 2015 |
| Send Technology Limited | Wholesale & retail | 2002 |
| Sensical Services Ltd | Information & communication | 2003 |
| Sfca Ltd | Administrative & support | 2020 |
| Shalbourne Beer Club Limited | Hospitality | 2025 |
| Shalbourne Soaring Society Limited | Arts & recreation | 1997 |
| Shandar Hospitality Limited | Hospitality | 2024 |
| Sheepdrove Education, Research and Outreach Ltd | Education | 2025 |
| Shefford Properties Limited | Real estate | 2026 |
| Showcase Exhibitions & Shopfitting Ltd | Construction | 2022 |
| Shropshire Savings and Loans Limited | Financial services | 2012 |
| SHY Property Ltd | Construction | 2019 |
| Signature I&A Cleaning Ltd | Administrative & support | 2026 |
| Signet Cabling Solutions Limited | Information & communication | 2025 |
| Silkmoth Group Limited | Financial services | 2016 |
| Silkmoth Limited | Information & communication | 2001 |
| Simon K Wake & Associates Ltd | Administrative & support | 2018 |
| Simplitrade Ltd | Information & communication | 2021 |
| Sirius Regulatory Consulting Limited | Administrative & support | 2007 |
| Siroda Limited | Information & communication | 2003 |
| Siso Property Limited | Real estate | 2024 |
| SK Electronix UK Limited | Professional & scientific | 2023 |
| Skirnir Limited | Real estate | 2026 |
| Skyla Consultancy Limited | Professional & scientific | 2020 |
| Skylark UK Bidco Limited | Financial services | 2023 |
| Skylark UK Debtco Limited | Financial services | 2023 |
| Skylark UK EUR Finco Limited | Financial services | 2023 |
| Skylark UK Holdco 1 Limited | Financial services | 2023 |
| Skylark UK Holdco 2 Limited | Financial services | 2023 |
| Skylark UK Midco Limited | Financial services | 2023 |
| Skylark UK Topco Limited | Financial services | 2023 |
| Skylark UK USD Finco Limited | Financial services | 2023 |
| Skynamo Limited | Information & communication | 2017 |
| Slatter Cricket & Play Ltd | Construction | 2021 |
| Slatter Holdings Ltd | Financial services | 2022 |
| Sleeping Giant Technologies Limited | Information & communication | 2024 |
| SLM Quantity Surveying Services Limited | Other services | 2016 |
| Smart Strength Studio UK Limited | Arts & recreation | 2024 |
| Smwg Recruitment Middle East Ltd | Administrative & support | 2020 |
| Solo Estates 2007 Limited | Real estate | 2007 |
| Solugenius Limited | Administrative & support | 2023 |
| Somborne Valley Research Ltd | Professional & scientific | 2016 |
| Some Media Group Limited | Information & communication | 2025 |
| Soshiq UK Limited | Wholesale & retail | 2018 |
| Sotto London Ltd | Hospitality | 2023 |
| Sound Footings Ltd | Professional & scientific | 2016 |
| Sourdough Sophia Covent Garden Limited | Wholesale & retail | 2026 |
| Sourdough Sophia Middle Lane Limited | Wholesale & retail | 2026 |
| Sourdough Sophia Primrose Hill Limited | Wholesale & retail | 2026 |
| Sourdough Sophia Production Limited | Manufacturing | 2025 |
| South Cornwall Developments LLP | | 2023 |
| South Western Investments Ltd | Real estate | 2020 |
| Southern Management Limited | Real estate | 1996 |
| Southern Properties Limited | Real estate | 2014 |
| Southern Residential Holdings Limited | Real estate | 2018 |
| Southern Residential Limited | Real estate | 2008 |
| Southern Residential Two Limited | Real estate | 2010 |
| Southern Sailplanes Limited | Manufacturing | 1983 |
| Southridge Properties Ltd | Construction | 2017 |
| Southwest Coffee Storage and Engineering Limited | Wholesale & retail | 2024 |
| Southwest Coffee Training Ltd | Wholesale & retail | 2025 |
| Spar Labs Limited | Information & communication | 2023 |
| Spar Properties Limited | Real estate | 2019 |
| Sparkle and Magic Ltd | Hospitality | 2022 |
| Speakeasy Entertainment Holdings Limited | Financial services | 2024 |
| Speakeasy Entertainment Ltd | Hospitality | 2008 |
| Spectrolab Systems Limited | Manufacturing | 1998 |
| Spin City Aerial Sports Newbury Ltd | Arts & recreation | 2022 |
| Sporting Agenda Ltd | Arts & recreation | 2004 |
| Sporting and General Supply (Shrewsbury) Limited | Wholesale & retail | 1969 |
| Spot Developments Limited | Real estate | 2015 |
| SRM Ventures Ltd | Professional & scientific | 2012 |
| SRN Medicolegal Services Limited | Information & communication | 2024 |
| SRN Property Holdings Limited | Real estate | 2020 |
| Srtc Ltd | Information & communication | 2018 |
| SS Groundworks & Construction Limited | Construction | 2012 |
| ST Mary's Hill Management Company Limited | Households | 2021 |
| ST Michaels Close (5 & 7 Freehold) Ltd. | Real estate | 2017 |
| ST Pierre Partners Limited | Wholesale & retail | 2014 |
| Stable IT Systems Limited | Information & communication | 2005 |
| Stag Service Station Ltd | Wholesale & retail | 2025 |
| Stairway Solutions Limited | Construction | 2007 |
| Stanley Moore Property Limited | Hospitality | 2014 |
| Stanton Motorsports Ltd | Manufacturing | 2026 |
| Stanwyck Food Limited | Hospitality | 2024 |