| Solterra Property Solutions Ltd | Construction | 2023 |
| Solutions 24X7 Limited | Professional & scientific | 2010 |
| Solutionsdotnet Limited | Information & communication | 2010 |
| Solé Aesthetics & Beauty Ltd | Other services | 2026 |
| SOM & Aram Ltd | Professional & scientific | 2025 |
| Someone to Talk to Ltd | Administrative & support | 2021 |
| Sonavi Mortgages Ltd | Financial services | 2025 |
| Sonder Clothing Limited | Wholesale & retail | 2023 |
| Soni Hair & Beauty Ltd | Wholesale & retail | 2011 |
| Sonic Enterprises Limited | Administrative & support | 1997 |
| Sonnet Care Homes Finance Limited | Professional & scientific | 2013 |
| Sonnet Care Homes Holdco Limited | Professional & scientific | 2013 |
| Sonnet Care Homes Midco Limited | Extraterritorial | 2013 |
| Sonocore Ltd | Health & social care | 2025 |
| Sophie Jones Limited | Administrative & support | 2006 |
| Sophie’S Tailoring Ltd | Wholesale & retail | 2026 |
| SOS2 Limited | Information & communication | 2024 |
| Souksales Ltd | Wholesale & retail | 2018 |
| Soul Stew Limited | Hospitality | 2023 |
| Soundspace Solutions Ltd | Construction | 2014 |
| Soundwaveslighting Catering Ltd | Hospitality | 2025 |
| South East Care Services Limited | Extraterritorial | 1988 |
| South East Housing Developments Limited | Construction | 2021 |
| South East Sports Ltd | Administrative & support | 2023 |
| Southern X Services Limited | Construction | 2019 |
| Southlea Property Management Limited | Construction | 2016 |
| Southwold Road (Block C) RTM Company Limited | Households | 2010 |
| Sovereign Glass & Glazing Limited | Construction | 2002 |
| Sozye Limited | Hospitality | 2019 |
| SP & M Ltd | Manufacturing | 2025 |
| Sp&Lm Ltd | Administrative & support | 2025 |
| SP1 Management Services Limited | Hospitality | 2022 |
| SP2 Management Services Limited | Hospitality | 2022 |
| Spa Business Services Limited | Information & communication | 2003 |
| Spa Enterprise Services Limited | Information & communication | 2009 |
| Spa Group Holdings Limited | Financial services | 2026 |
| Space International Limited | Wholesale & retail | 2016 |
| Spare Throne Limited | Real estate | 2011 |
| Spark of Genius North East LLP | | 2013 |
| Spark of Genius Woodside Property Limited | Real estate | 2024 |
| Sparkly Foods & Beverages Ltd | Manufacturing | 2025 |
| Sparkydodo Ltd | Professional & scientific | 2020 |
| Sparrows Crew Limited | Construction | 2018 |
| Spatial-Sci Limited | Professional & scientific | 2019 |
| SPB Transport and Logistics Ltd | Transport & logistics | 2026 |
| Special Consulting Ltd | Information & communication | 2025 |
| Special Sales Limited | Wholesale & retail | 2021 |
| Specialised Global Distribution (UK) Limited | Transport & logistics | 2009 |
| Specialist Body Imaging Ltd | Health & social care | 2009 |
| Specialist Operations Academy Limited | Administrative & support | 2017 |
| Spectra Spark Studios Ltd | Arts & recreation | 2024 |
| Speechless CIE Ltd | Information & communication | 2016 |
| Speedyfix Auto Sales Limited | Wholesale & retail | 2025 |
| Spence Foods Limited | Wholesale & retail | 2025 |
| Spencer Contracting Services Limited | Professional & scientific | 2017 |
| Spgc Ltd | Administrative & support | 2016 |
| Sphintech Ltd | Information & communication | 2025 |
| Spice & Herbs Ltd | Wholesale & retail | 2020 |
| Spice Afrik Ltd | Hospitality | 2025 |
| Spice Royale Ltd | Manufacturing | 2024 |
| Spider Access Limited | Extraterritorial | 2004 |
| Spinnaker Debtco Limited | Financial services | 2022 |
| Spinnaker Holdco Limited | Financial services | 2022 |
| Spinnaker Midco Limited | Financial services | 2022 |
| Spire Property Holdings UK Limited | Real estate | 2021 |
| Spitfireecommerce Ltd | Wholesale & retail | 2024 |
| Spjk Investments Ltd | Real estate | 2021 |
| Spjk Ltd | Other services | 2019 |
| Splendida Cruise Limited | Transport & logistics | 2024 |
| Splinter Sets Ltd | Construction | 2020 |
| Sport Access Ltd | Extraterritorial | 2011 |
| Spot on Beauty Ltd. | Other services | 2020 |
| Spotlight Music Limited | Other services | 2011 |
| Spotlight Party Plus Ltd | Arts & recreation | 2023 |
| Spps Holdings Management Limited | Professional & scientific | 2023 |
| Spraytown Autos Ltd | Wholesale & retail | 2025 |
| Spring Cleaning Limited | Administrative & support | 2011 |
| Spring Health Managed Services Ltd | Health & social care | 2019 |
| Spring Software Limited | Information & communication | 2010 |
| Springboard West Limited | Education | 2011 |
| Springboks Real Estate UK Ltd | Real estate | 2017 |
| Sprintnova Ltd | Wholesale & retail | 2024 |
| Spurway Foods Limited | Manufacturing | 1992 |
| Spusu UK Ltd. | Information & communication | 2020 |
| Square Bubbles Uxbridge Ltd | Wholesale & retail | 2026 |
| Square House Homes Limited | Construction | 2017 |
| Square House Resources Ltd | Administrative & support | 2018 |
| Square Plan Limited | Professional & scientific | 2017 |
| Square Roots Registered Provider Limited | Real estate | 2020 |
| Sqube Technologies Ltd | Information & communication | 2018 |
| SR Foods & Ingredients Ltd | Hospitality | 2012 |
| SR Sangha Construction Ltd | Construction | 2020 |
| SR Timber & Building Merchant Ltd | Wholesale & retail | 2024 |
| SRB Consultancy UK Limited | Administrative & support | 2019 |
| SRH Homes Limited | Construction | 2022 |
| SRI SRI Maharajji Consultant Limited | Construction | 2012 |
| Srila Food Ltd | Hospitality | 2023 |
| SRK Pound Plus Limited | Wholesale & retail | 2024 |
| SRK Traders Limited | Wholesale & retail | 2007 |
| Srmr Properties Limited | Real estate | 2026 |