| Soulfly Limited | Arts & recreation | 2014 |
| Soundhr Ltd | Administrative & support | 2018 |
| Source Food Limited | Manufacturing | 2024 |
| South Quay Capital Limited | Financial services | 2015 |
| South West London Home Improvement Agency CIC | Health & social care | 2013 |
| Spacepointe Ltd | Information & communication | 2024 |
| Spader Specialist Trauma Clean Ltd | Other services | 2024 |
| Spaniel Properties Holdings Limited | Real estate | 2022 |
| Spanimmersion Ltd | Professional & scientific | 2021 |
| Spanish Activities Limited | Hospitality | 2024 |
| Sparkling Limited | Other services | 2016 |
| Spary Ltd | Real estate | 2026 |
| SPC Hitchin Limited | Wholesale & retail | 2016 |
| SPC Rigging and Automation Ltd | Construction | 2018 |
| SPC Trading Limited | Other services | 2015 |
| Spe@Dy Services Ltd | Wholesale & retail | 2016 |
| Spec Car Ltd | Wholesale & retail | 2019 |
| Special Care Medical Services Limited | Health & social care | 2012 |
| Specialist Sheet Metal Ltd | Manufacturing | 2007 |
| Specialist Solutions Corporate Investigations Ltd | Administrative & support | 2015 |
| Specialty Electronic Materials UK Limited | Wholesale & retail | 2016 |
| Spectrum Services Corporation Limited | Health & social care | 2013 |
| Speed&Quality Construction Limited | Construction | 2022 |
| Speedex Couriers Limited | Transport & logistics | 2007 |
| Speedmoving Limited | Administrative & support | 2015 |
| Speedway Ride N Slide Dayz Limited | Arts & recreation | 2011 |
| Speedy Spanner Ltd | Wholesale & retail | 2018 |
| Spencer Wood Magic Limited | Arts & recreation | 2015 |
| Spice Realty Ltd | Real estate | 2021 |
| Spirate UK Limited | Other services | 2023 |
| Spire Roofing Limited | Construction | 2015 |
| SPL Hold Co Limited | Other services | 2020 |
| Splaat Media Limited | Professional & scientific | 2014 |
| SPM Engineering Consultancy Limited | Administrative & support | 2014 |
| Sport Fusion Ltd | Arts & recreation | 2025 |
| Sporting Futures Training (UK) Ltd | Education | 2014 |
| Spotta Fitness Ltd | Health & social care | 2023 |
| Spray Nova Ltd | Construction | 2024 |
| Springburn Brickwork Contractors Ltd | Construction | 2014 |
| Springston Investments Limited | Real estate | 2023 |
| Sprintwave Services Ltd | Information & communication | 2026 |
| Spur Therapeutics Holdings Limited | Financial services | 2023 |
| Spur Therapeutics Limited | Professional & scientific | 2015 |
| Spyglass Insights Limited | Information & communication | 2015 |
| Square Locum Limited | Wholesale & retail | 2014 |
| SR Palette Electrical Services Ltd | Construction | 2020 |
| SRA Global Distribution Ltd | Wholesale & retail | 2021 |
| Sram Transport Ltd | Transport & logistics | 2025 |
| SRD Property Services Ltd | Construction | 2024 |
| SRG Studio Limited | Professional & scientific | 2024 |
| SRM Services Ltd | Construction | 2009 |
| SRN Financial Services Limited | Professional & scientific | 2020 |
| SRS Consulting Limited | Professional & scientific | 2020 |
| SRW Land & Lawn Ltd | Administrative & support | 2025 |
| SS Direct Services Limited | Other services | 2019 |
| SS Rigging Services Ltd | Construction | 2024 |
| SSC Survey and Engineering Ltd | Construction | 2018 |
| SSM Electrical Services Ltd | Construction | 2022 |
| ST Andrews Rectory Flats Ltd | Households | 2011 |
| ST Georges Brothers Limited | Transport & logistics | 2025 |
| ST John Street Property Services Limited | Extraterritorial | 2018 |
| ST. Andrews Terrace Residents Association Limited | Households | 1991 |
| St.Evenage Estates Limited | Real estate | 2022 |
| ST4G Ltd | Wholesale & retail | 2023 |
| ST4G Tech 4 Change Ltd | Information & communication | 2022 |
| Stadium Grass Group Ltd | Professional & scientific | 2024 |
| Stafford Keep Management Company Limited | Households | 2003 |
| Stag Property Maintenance Limited | Wholesale & retail | 2010 |
| Stage & Screen Film Transportation Ltd | Information & communication | 2023 |
| Stanart Consultancy Ltd | Professional & scientific | 2021 |
| Stanley Street Limited | Real estate | 2021 |
| Stanmo Limited | Health & social care | 2013 |
| Star Apartments Management Company Limited | Households | 2005 |
| Star Autotech Limited | Wholesale & retail | 2022 |
| Star Business Services Limited | Information & communication | 2017 |
| Starfield Studio Limited | Arts & recreation | 2024 |
| Starr Tradings Limited | Wholesale & retail | 2016 |
| Start 2 Finish (UK) Ltd | Information & communication | 2013 |
| Start Cleaning Products Ltd | Administrative & support | 2024 |
| Start Point Education Ltd | Education | 2023 |
| Station Parade LGC Limited | Real estate | 2012 |
| Station Road Chadwell Flat Management Company (Block a) Limited | Households | 1989 |
| Stcp Ltd | Information & communication | 2022 |
| Steadfast Construction and Engineering Ltd | Construction | 2014 |
| Steadfast UK Holdings Limited | Other services | 2021 |
| Steam and Pressure Solutions Limited | Administrative & support | 2023 |
| Stedefast Ltd | Real estate | 2024 |
| Steel Works Creative Ltd | Arts & recreation | 2025 |
| Steer Clear Instruction Ltd | Education | 2025 |
| Stempoint | Education | 2002 |
| Step by Step Mentoring Ltd | Other services | 2025 |
| Step Change Outsourcing Limited | Information & communication | 2007 |
| Step UP Property Ltd | Real estate | 2018 |
| Stephanie Dyment Limited | Information & communication | 2014 |
| Stephen Alexander Building Services Limited | Construction | 2018 |
| Stephen Johns Music Ltd | Information & communication | 2023 |
| Sterling & Fletcher Ltd | Construction | 2026 |
| Sterling B Stitches Ltd | Manufacturing | 2025 |
| Sterling Management Support Limited | Administrative & support | 2025 |
| Steve Barber Media Limited | Arts & recreation | 2018 |