| Square Brick Investments Limited | Financial services | 2022 |
| Square Brick Offices Limited | Real estate | 2024 |
| Square Fish Events Ltd | Administrative & support | 2020 |
| Square Root 3 Ltd | Financial services | 2023 |
| Squared Circle Communication Ltd | Administrative & support | 2023 |
| Squidd Limited | Other services | 2021 |
| Squires Park Travel Limited | Transport & logistics | 2023 |
| Sqwonk Squad Ltd | Manufacturing | 2018 |
| SR Consulting NW Ltd | Professional & scientific | 2026 |
| SR Power Engineering Services Ltd | Professional & scientific | 2017 |
| SR Quality Engineering Limited | Professional & scientific | 2018 |
| SR3 Solutions Limited | Administrative & support | 2011 |
| SRA Lettings Ltd | Real estate | 2015 |
| SRB Tax Limited | Professional & scientific | 2021 |
| SRC Property Ltd | Real estate | 2021 |
| SRD Coastal Properties Ltd | Real estate | 2025 |
| Srdjan Spremo Advertising Solutions Limited | Information & communication | 2016 |
| Sree Guru Technologies Limited | Administrative & support | 2025 |
| SRG Associates Limited | Professional & scientific | 2016 |
| SRG Food & Wine Ltd | Wholesale & retail | 2024 |
| SRG Mechanical Solutions Limited | Construction | 2019 |
| SRH Engineering Ltd | Administrative & support | 2023 |
| SRI Abinaya Services Limited | Information & communication | 2025 |
| SRI Sravana Nivas Limited | Real estate | 2021 |
| Srisha Healthcare Limited | Health & social care | 2017 |
| SRP UK Properties Ltd | Real estate | 2024 |
| Srpatel Consulting Limited | Professional & scientific | 2022 |
| SRR Law Limited | Professional & scientific | 2025 |
| SRR29 Consulting Limited | Information & communication | 2019 |
| SRS Floors Ltd | Wholesale & retail | 2024 |
| SRS Installations Ltd | Construction | 2023 |
| SS Consulting Services Ltd | Professional & scientific | 2013 |
| SS UK Properties Ltd | Construction | 2020 |
| Ssac Communications Limited | Professional & scientific | 2025 |
| SSD 360 Limited | Information & communication | 2018 |
| SSD Project Services Limited | Administrative & support | 2007 |
| Ssdv Limited | Information & communication | 2023 |
| SSK Consulting Ltd | Administrative & support | 2023 |
| SSK2 Consulting Limited | Health & social care | 2022 |
| SSL Software Solutions Ltd | Administrative & support | 2025 |
| SSS Storage Ltd. | Transport & logistics | 2017 |
| Sssm Limited | Administrative & support | 2014 |
| ST Aloysius CY32 Ltd | Administrative & support | 2025 |
| ST Annamma Limited | Hospitality | 2022 |
| ST Catering WA Ltd | Hospitality | 2024 |
| ST Francis Ltd | Hospitality | 2025 |
| ST George's Place RTM Company Limited | Hospitality | 2014 |
| ST Georges Place (Warrington) Management Company Limited | Households | 2003 |
| ST Helens Independent Medical Clinic LLP | | 2011 |
| ST Helens Scrap Metal Limited | Wholesale & retail | 2015 |
| ST Ives Brewery Limited | Manufacturing | 2010 |
| ST John Software Limited | Information & communication | 2019 |
| ST Mary & ST George Ltd | Other services | 2026 |
| ST Project Engineering Ltd | Professional & scientific | 2017 |
| ST. George's Rise (Management Company) Limited | Administrative & support | 2010 |
| ST. Helens Site Limited | Real estate | 2018 |
| ST. Rocco's Hospice | Health & social care | 1981 |
| ST. Rocco's Promotions Limited | Arts & recreation | 1995 |
| ST. Rocco's Shops Limited | Wholesale & retail | 1990 |
| ST61 Dynamics Consulting Ltd | Professional & scientific | 2025 |
| Stablez One Ltd | Hospitality | 2021 |
| Staceley Services Ltd | Hospitality | 2025 |
| Stacey & Clem Estates Limited | Real estate | 2024 |
| Stacey Flooring Limited | Construction | 2015 |
| Stacked Shrewsbury Limited | Hospitality | 2026 |
| Stafford Delivery Services Ltd | Transport & logistics | 2021 |
| Stafie Mihai Ltd | Transport & logistics | 2019 |
| Stag Skate Investments | Financial services | 2022 |
| Stage Marketing Ltd | Professional & scientific | 2019 |
| Stagepro Academy Ltd | Arts & recreation | 2018 |
| Staincliffe Jones Ltd | Real estate | 2006 |
| Stalet Properties Limited | Real estate | 2004 |
| Stamentum Limited | Professional & scientific | 2019 |
| Stamford Life Capital Limited | Financial services | 2019 |
| Stamp OUT Suicide Limited | Health & social care | 2015 |
| Stamper Landscapes Ltd | Manufacturing | 2018 |
| Stancad Elite Ltd | Professional & scientific | 2018 |
| Stand Fast 2 Limited | Real estate | 2021 |
| Stand Fast Limited | Real estate | 2017 |
| Standalone Professional Services Ltd | Information & communication | 2019 |
| Standard Work Limited | Administrative & support | 2007 |
| Standards Plus Ltd | Professional & scientific | 1996 |
| Standing Space Limited | Professional & scientific | 2015 |
| Standingfauld Limited | Financial services | 2020 |
| Standish Chiropractor Clinic Limited | Health & social care | 2023 |
| Stanfield Marine Solutions Ltd | Administrative & support | 2025 |
| Stanforth Engineering Ltd | Administrative & support | 2025 |
| Stanicel Ltd | Transport & logistics | 2018 |
| Stanier 8F Locomotive Society Limited (the) | Arts & recreation | 1970 |
| Stanislaw Golyzniak Transport Ltd. | Transport & logistics | 2016 |
| Stanley & Co UK Ltd | Construction | 2023 |
| Stanley Brickwork Ltd | Construction | 2022 |
| Stanley Housing Ltd | Real estate | 2016 |
| Stanley Wines Lingley Ltd | Wholesale & retail | 2026 |
| Stanley-Day Padel Ltd | Construction | 2023 |
| Stanley-Day Plant Hire Ltd | Administrative & support | 2025 |
| Stanleyred Developments Ltd | Construction | 2025 |
| Stansfield Court Management Company Limited | Households | 2009 |
| Stantec Europe Limited | Professional & scientific | 1989 |
| Stantec Global Capital Limited | Professional & scientific | 2017 |