| Roblec Properties (Muswell Hill) Limited | Real estate | 1964 |
| Robust & Portable Limited | Information & communication | 1998 |
| Rock the BUS Camper Van Hire Limited | Administrative & support | 2007 |
| Rockport Holdings Limited | Professional & scientific | 2007 |
| Romeo Travel Limited | Administrative & support | 1985 |
| Roomend | | 1998 |
| RP Concrete Components Limited | Wholesale & retail | 2025 |
| Rtnt Limited | Wholesale & retail | 2018 |
| Russell & Butler Limited | Real estate | 2001 |
| S & B Management Initiatives Ltd | Information & communication | 1993 |
| S J Lucas Consulting Limited | Professional & scientific | 2017 |
| S. DAD Limited | Real estate | 1999 |
| SA Physio Care Ltd | Health & social care | 2025 |
| SA Wholesale Limited | Administrative & support | 2003 |
| SAA Engineering Limited | Professional & scientific | 2020 |
| Sacred Footsteps Ltd | Other services | 2020 |
| Safety International Limited | Other services | 2007 |
| Salex Acoustics Limited | Construction | 2005 |
| Salex Limited | Extraterritorial | 2005 |
| Samuel Leeds Developments (WH) Ltd | Hospitality | 2023 |
| Sandelswood END (Beaconsfield) Residents Limited | Households | 2003 |
| Savage Engineer Limited | Manufacturing | 1997 |
| SBS GRP Limited | Wholesale & retail | 2022 |
| Sci-Tek Instruments Limited | Professional & scientific | 1999 |
| Scott Cutters Limited | Administrative & support | 2007 |
| Scott Health and Wellbeing Ltd | Health & social care | 2023 |
| Screem Ltd | Information & communication | 2024 |
| Seamless Industries Ltd | Wholesale & retail | 2005 |
| Seatidelamps Ltd | Wholesale & retail | 2025 |
| SEE Solutions Ltd | Information & communication | 2021 |
| Seebeck Limited | Professional & scientific | 1993 |
| Sense Healthcare Ltd | Health & social care | 2024 |
| Seraa 5 Trading Limited | Real estate | 2024 |
| Service Developments Holdings Limited | Real estate | 1996 |
| SFG Solutions Ltd | Professional & scientific | 2005 |
| Sgcs Sales and Services Limited | Transport & logistics | 1919 |
| Shadu Enterprises (UK) Ltd | Real estate | 2001 |
| Shardeloes Farm Equestrian Centre Limited | Arts & recreation | 1999 |
| Sharry Ltd | Wholesale & retail | 2003 |
| Shashi Bhardwaj Limited | Health & social care | 1999 |
| Shearaco Limited | Professional & scientific | 2004 |
| Shepperton Studios Property Partnership | | 2006 |
| Sheraton Developments Limited | Real estate | 1997 |
| Shine Coaching and Consultancy Limited | Education | 2008 |
| Shizentai Health and Exercise Limited | Arts & recreation | 2007 |
| Shoreham Lane Limited | Real estate | 2022 |
| Shrigajanan Holdings Limited | Financial services | 2018 |
| Shrigajanan Properties Limited | Real estate | 2018 |
| Siarey's of Chinnor Limited | Professional & scientific | 1971 |
| Sidal Limited | Real estate | 2006 |
| Signrite Services Limited | Construction | 2007 |
| Silentmonkey AI Ltd | Manufacturing | 2026 |
| Silver Back Marketing Limited | Administrative & support | 2005 |
| Silver Dialogue Limited | Professional & scientific | 2002 |
| Simon Design Limited | Wholesale & retail | 2001 |
| Sisson Building Company Limited | Construction | 2005 |
| SK Village Properties Ltd | Real estate | 2025 |
| Skandha Software Limited | Information & communication | 2026 |
| Skratchit Media Ltd | Information & communication | 1999 |
| Skyblue Info Systems Limited | Information & communication | 2010 |
| Slide Analysis UK Ltd | Professional & scientific | 2026 |
| Small Planet Meetings Ltd | Administrative & support | 2002 |
| Smart Kids Ltd | Extraterritorial | 1998 |
| Smart Recruit Online Limited | Information & communication | 2011 |
| SMC Design Limited | Professional & scientific | 1993 |
| SMG Computing Limited | Information & communication | 2007 |
| Sola Furniture Limited | Professional & scientific | 1992 |
| Solutions Holdings Limited | Professional & scientific | 1997 |
| Sorb Engineers Limited | Manufacturing | 2001 |
| Sorbon Group Limited | Construction | 1998 |
| Sorbon Interiors Limited | Extraterritorial | 2003 |
| Sorbon Investments Limited | Construction | 1998 |
| Soul Bros.Limited | Transport & logistics | 1962 |
| Southern Ceramic Supplies Limited | Manufacturing | 1982 |
| Sovereign Place (Wallingford) Limited | Households | 2001 |
| SP Suppliers Limited | Other services | 2019 |
| SP T&K Limited | Real estate | 2025 |
| Spinnaker Business Services Limited | Professional & scientific | 2001 |
| Spiritus Design Limited | Administrative & support | 2007 |
| Sportmode Management Ltd | Arts & recreation | 2005 |
| Sports Management Consulting Corporation Limited | Professional & scientific | 1999 |
| Sports Republic Limited | Wholesale & retail | 2017 |
| Spraytech (Aylesbury) Limited | Wholesale & retail | 2002 |
| Springchase Limited | Information & communication | 1989 |
| SPVAL52 Limited | Real estate | 2022 |
| Spyre Limited | Professional & scientific | 2003 |
| SRI SAI Investments Ltd | Real estate | 2019 |
| SSJ Enterprises Limited | Information & communication | 2007 |
| ST Peter Investments Limited | Professional & scientific | 1982 |
| ST. Huberts Court (Management) Company Limited | Households | 1997 |
| ST. Huberts Properties Limited | Real estate | 2000 |
| St.Mary's School,Gerrards Cross,Limited | Education | 1944 |
| Stamon Group Limited | Real estate | 2020 |
| Staragon Holdings Ltd | Financial services | 2025 |
| Starmist Consulting Ltd | Education | 1998 |
| Stellarsparklamps Ltd | Wholesale & retail | 2025 |
| Stewart and Clark Associates Limited | Professional & scientific | 1988 |
| Stoney Lane Productions Limited | Information & communication | 2004 |
| Stowe House Enterprises Limited | Arts & recreation | 1998 |
| Stratadviser Limited | Professional & scientific | 2007 |