| Sparkling Sisters Ltd | Administrative & support | 2021 |
| Sparta Electrical Contractors Ltd | Construction | 2025 |
| Sparta Rend Ltd | Construction | 2019 |
| Spartan Restoration Ltd | Construction | 2021 |
| Special Cleaning DRM Ltd | Administrative & support | 2025 |
| Specialist Gymnastics Services Ltd | Arts & recreation | 2018 |
| Speciality Beans Ltd. | Manufacturing | 2017 |
| Spectar Limited | Professional & scientific | 2015 |
| Spectron GCS UK Limited | Administrative & support | 2009 |
| Spectrum Solutions Limited | Administrative & support | 2021 |
| Spectrum Valley Properties Limited | Real estate | 2022 |
| Speed Speak Limited | Professional & scientific | 2021 |
| Speedweeder Ltd | Information & communication | 2015 |
| Speedy Frog Window Sales Limited | Construction | 2014 |
| Sphere Controls Ltd | Administrative & support | 2018 |
| Spice Lounge Ltd | Hospitality | 2023 |
| Spinnaker Insight Estates Ltd | Real estate | 2024 |
| Spire Care Ltd | Health & social care | 2021 |
| Spire CT. Management Company Ltd | Households | 2024 |
| Spire Housing Investments Limited | Real estate | 2018 |
| Spire Housing Limited | Real estate | 2003 |
| Spirit Centre SKF Dojo Gym & Studio Limited | Arts & recreation | 2025 |
| Splash Water Play Limited | Administrative & support | 2007 |
| Splendid Pizza Ltd | Hospitality | 2020 |
| Splendourz B&L Limited | Construction | 2013 |
| Spmk Developments Ltd | Construction | 2023 |
| Spmk Holdings Ltd | Construction | 2023 |
| Spondee Ltd | Transport & logistics | 2022 |
| Sport, Health & Fitness Limited | Administrative & support | 2016 |
| SPORTING4SCHOOLS YSL Ltd | Education | 2025 |
| Sports Academy Coaching Limited | Arts & recreation | 2014 |
| Sports Ground Services Limited | Administrative & support | 2020 |
| Spot-On Construction and Maintenance Ltd | Construction | 2025 |
| Spots and Stripes Leisure Limited | Arts & recreation | 2019 |
| Spresso House Ltd | Hospitality | 2026 |
| Spring & Co. Developments Ltd | Real estate | 2025 |
| Spring Parkway Ltd | Real estate | 2023 |
| Springcroft Investments Limited | Real estate | 2026 |
| Sprint Wholesale Ltd | Wholesale & retail | 2011 |
| Spubby Services Limited | Wholesale & retail | 2025 |
| Spynet Finance Ltd | Financial services | 2020 |
| SQB Marbles Ltd | Wholesale & retail | 2020 |
| Square Hotels Ltd | Hospitality | 2026 |
| Square Interactive Design Limited | Professional & scientific | 2000 |
| Square Stool Ltd | Wholesale & retail | 2026 |
| Squaregain Capital Ltd | Financial services | 2020 |
| SR Film Limited | Professional & scientific | 2015 |
| SR Film Production Limited | Professional & scientific | 2015 |
| SRB Partnership Homes Ltd | Real estate | 2024 |
| SRB Partnership Limited | Health & social care | 2020 |
| Srch Limited | Financial services | 2005 |
| SRI SAI Consultants Limited | Other services | 2015 |
| Sridattatreya Ltd | Information & communication | 2017 |
| Srigowriepala & Sugirthathevy Property Flippers Limited | Construction | 2025 |
| Srivijarn Group Co. Ltd | Financial services | 2024 |
| Srose Enterprise Ltd | Other services | 2024 |
| SRS Infotech Limited | Information & communication | 2018 |
| Srss Techno Solutions Ltd | Information & communication | 2025 |
| SRW Accounting Limited | Professional & scientific | 2022 |
| SS Bespoke Solutions (UK) Limited | Professional & scientific | 2017 |
| SS Pro Healthcare Limited | Health & social care | 2025 |
| SS Service Limited | Transport & logistics | 2014 |
| SS Trading Solutions Ltd | Construction | 2024 |
| SS1 Estates Ltd | Real estate | 2024 |
| SSAM5 Limited | Administrative & support | 2015 |
| SSB Coaching and Sports Ltd | Education | 2025 |
| SSB Infotech Limited | Information & communication | 2021 |
| SSB Property and Investments Ltd | Real estate | 2021 |
| SSM Motors Ltd | Wholesale & retail | 2026 |
| SSN Homes Ltd | Real estate | 2023 |
| Ssrm Construction Ltd | Construction | 2025 |
| Sssk Trading Ltd | Wholesale & retail | 2020 |
| ST Cecilia Wind Symphony Limited | Arts & recreation | 2021 |
| ST Georges Removals and Storage Limited | Real estate | 2013 |
| ST Laurence Retreat Ltd | Hospitality | 2022 |
| ST Lukes Yard Freehold Limited | Administrative & support | 2014 |
| ST Marys Holdings Limited | Financial services | 2026 |
| ST Scenic Services Ltd | Construction | 2025 |
| ST Vincents Insulation Ltd. | Manufacturing | 1998 |
| ST Wealth Consultancy Ltd | Professional & scientific | 2025 |
| Stack to Heap Ltd | Information & communication | 2025 |
| Stackerlive Ltd | Information & communication | 2026 |
| Stade Estate Ltd | Real estate | 2026 |
| Stag Consult Limited | Administrative & support | 2015 |
| Stag Management Ltd | Administrative & support | 2019 |
| Stage Left Services Ltd | Construction | 2022 |
| Stairways Solutions Ltd | Construction | 2025 |
| Stallion Developers Ltd | Real estate | 2017 |
| Stamate Aero Ltd | Information & communication | 2017 |
| Stampede Consulting Group Limited | Professional & scientific | 2026 |
| Stan Healthcare Ltd | Health & social care | 2016 |
| Stanbridge Limited | Manufacturing | 1956 |
| Stanbury Lettings Ltd | Real estate | 2019 |
| Standard Consulting Limited | Professional & scientific | 2022 |
| Standard Projects (Southern) Limited | Construction | 2013 |
| Standout Theatre Limited | Education | 2006 |
| Standrise Limited | Construction | 1992 |
| Stankudu Limited | Construction | 2015 |
| Stanrec Limited | Real estate | 2024 |
| Stansted Recycling Ltd | Transport & logistics | 2020 |