| Sparkle Sparkle Cleaning Limited | Administrative & support | 2025 |
| Sparrowhawk Enterprises Limited | Construction | 1993 |
| Special Tuning Abingdon Limited | Extraterritorial | 1994 |
| Special Tuning Limited | Extraterritorial | 1994 |
| Specialist Restorative Services Ltd | Health & social care | 2013 |
| Spectrum Support Services Limited | Hospitality | 2015 |
| Speedcamp Limited | Arts & recreation | 2021 |
| Speedcamp Management Ltd | Administrative & support | 2023 |
| Spencer Creative Ltd | Other services | 2023 |
| Spencer Newman Limited | Real estate | 1994 |
| Spencer Nicholls Ltd | Construction | 2015 |
| Sphere IT Consultants Limited | Information & communication | 2010 |
| Spice New Media Limited | Information & communication | 2012 |
| Spice Shoes Limited | Wholesale & retail | 1985 |
| Spicer Court Freehold Limited | Real estate | 2000 |
| Spicer Court Management Co. Limited | Households | 1993 |
| Spiers Decorating Contractors Limited | Construction | 1999 |
| Spikegate Limited | Administrative & support | 2002 |
| Spinning Dog Productions Ltd | Professional & scientific | 2014 |
| Spinsole Limited | Administrative & support | 2003 |
| Spire Mews (Finsbury Park) Limited | Real estate | 2026 |
| SPK Investments Limited | Real estate | 2016 |
| SPN GP Services Limited | Health & social care | 2015 |
| Sport Shoes UK Limited | Wholesale & retail | 2022 |
| Spra H Co Ltd | Administrative & support | 2026 |
| Spread the Love Grazing Limited | Hospitality | 2022 |
| Spring Garden Lane Properties Limited | Real estate | 2007 |
| Spring Management Inc. Limited | Wholesale & retail | 2019 |
| Springs Gilead Consulting Ltd | Information & communication | 2019 |
| Square Bidco Limited | Administrative & support | 2021 |
| Square Mile Clinic Ltd | Administrative & support | 2026 |
| Squibb Associates Ltd | Real estate | 2020 |
| SR Fencing Ltd | Construction | 2025 |
| SR Georgiou Properties Ltd | Real estate | 2024 |
| SRG Newmans Holdings Ltd | Financial services | 2020 |
| SRG Newmans Nexgen Ltd | Real estate | 2020 |
| SRG Newmans Property Investments Limited | Real estate | 2016 |
| SRJ IT Consulting Ltd | Information & communication | 2018 |
| SRM UK Holdings Ltd | Financial services | 2018 |
| SRW Trading Limited | Administrative & support | 2016 |
| Ssdn Ltd | Health & social care | 2025 |
| Sspk UK Trading Limited | Other services | 2009 |
| ST Stephens Mansions Monmouth Road Limited | Households | 2020 |
| ST. Annes Court Residents Company Limited | Households | 1996 |
| ST10 Futures Ltd | Administrative & support | 2026 |
| Stables and Lucraft Ltd | Administrative & support | 2017 |
| Stacey House Limited | Real estate | 1999 |
| Stage Door West END Ltd | Hospitality | 2024 |
| Stained Glass Art Studio Ltd | Manufacturing | 2026 |
| Stallion Estates Limited | Hospitality | 2004 |
| Stanmore Group Residential Limited | Real estate | 2025 |
| Star Noir Creative Ltd | Wholesale & retail | 2025 |
| Startup Office Limited | Extraterritorial | 2011 |
| State Centre Limited | Other services | 2017 |
| Station Road (Langley Mill) Ltd | Real estate | 2018 |
| STB Finance Ltd | Financial services | 2018 |
| STE Computers Ltd. | Information & communication | 2011 |
| Steins Foods Ltd | Wholesale & retail | 2009 |
| Stella-Works Limited | Professional & scientific | 2009 |
| Stephanie Jayne Nutrition Ltd | Health & social care | 2020 |
| Stepping Stone Builders Ltd | Extraterritorial | 2012 |
| Stereogram Ltd | Manufacturing | 2020 |
| Stern Accountancy Services Limited | Professional & scientific | 2004 |
| Steven Gordon Limited | Professional & scientific | 2011 |
| Steven Pearce Limited | Construction | 2010 |
| STI Internazionale (UK) Limited | Transport & logistics | 2020 |
| Stillware Ltd | Information & communication | 2025 |
| Stipe Limited | Administrative & support | 2016 |
| Stirling Management & Services Limited | Real estate | 2003 |
| Stitched London Limited | Manufacturing | 2025 |
| Stock Nation Ltd | Wholesale & retail | 2024 |
| Stokes & Jolly Consulting Limited | Professional & scientific | 2008 |
| Stomatologica Services Ltd | Administrative & support | 2013 |
| Stone Piers Limited | Construction | 2021 |
| Stone Scape Masons Limited | Construction | 2025 |
| Stonecastle Estates Ltd | Real estate | 2024 |
| Stoneview Group Ltd | Real estate | 2023 |
| Storgizo Investments Ltd | Real estate | 2023 |
| Storyhouse Design and Production Ltd | Administrative & support | 2021 |
| Storyhouse Events Ltd | Extraterritorial | 2019 |
| Stowing Limited | Households | 1974 |
| Strachan Design Associates Limited | Professional & scientific | 1977 |
| Stratagem Quest LP | | 2024 |
| Streamline Consulting Services Ltd | Professional & scientific | 2018 |
| Strictly Chair Yoga Ltd | Other services | 2018 |
| Strike Investments Ltd | Real estate | 2009 |
| Strike Leisure Ltd | Hospitality | 2003 |
| Stringz Limited | Professional & scientific | 2022 |
| Stripe Music Ltd | Arts & recreation | 2009 |
| Strongholding Limited | Real estate | 2016 |
| Stubwick Ltd | Manufacturing | 2015 |
| Studio 21 Limited | Manufacturing | 2019 |
| Studio Fifty-Four London Limited | Information & communication | 2019 |
| Studio Sixty-One Limited | Information & communication | 2014 |
| Studio Thameswater Ltd | Arts & recreation | 2022 |
| Stvfm Ltd | Households | 2021 |
| Stylianou Group Ltd | Real estate | 2022 |
| Stylus Live Limited | Arts & recreation | 2023 |
| Suburban Estates Limited | Real estate | 2000 |
| Sudha Girish Limited | Health & social care | 2016 |