| Sumalink Ltd | Information & communication | 2025 |
| Sumerian Motors Limited | Wholesale & retail | 2026 |
| Summit Care Group 1 Limited | Health & social care | 2025 |
| Summit Care Group Limited | Health & social care | 2024 |
| Summit Chauffeur Service Ltd | Transport & logistics | 2012 |
| Summit Sales (UK) Ltd | Professional & scientific | 2011 |
| Sumnima Entertainment UK Ltd | Hospitality | 2023 |
| Sumoy Estates Limited | Real estate | 2024 |
| Sumoy Group Limited | Real estate | 2024 |
| Sundi Pharma Limited | Wholesale & retail | 2008 |
| Sunglobe Trading Limited | Administrative & support | 2020 |
| Sunjoy International (UK) Ltd | Wholesale & retail | 2022 |
| Sunny Aviation Ltd | Professional & scientific | 2024 |
| Sunrise Mortgage Ltd | Financial services | 2018 |
| Sunshine Nurseries Limited | Health & social care | 2003 |
| Suntan Industries (UK) Limited | Wholesale & retail | 2004 |
| Superaint London Ltd | Wholesale & retail | 2019 |
| Superchoice London Limited | Wholesale & retail | 2015 |
| Superus Healthcare Limited | Professional & scientific | 2022 |
| Supplisync Ltd | Professional & scientific | 2026 |
| Supply for Learning Limited | Education | 2016 |
| Supra & Co Ltd | Professional & scientific | 2011 |
| Supra Investments (UK) Ltd | Real estate | 2021 |
| Supreme Engineers & Enterprises Limited | Construction | 2007 |
| Supreme Pharma Ltd | Wholesale & retail | 2024 |
| Sure Heating Services Limited | Construction | 2021 |
| Surelock Asset Management Limited | Administrative & support | 1993 |
| Surrey Restoration Specialists Ltd | Construction | 2013 |
| Surrey Roofing and Property Maintenance Limited | Construction | 2023 |
| Sustainability 4 ALL Ltd | Professional & scientific | 2023 |
| Sutton COD Spot Limited | Hospitality | 2024 |
| Sutton Systems Ltd | Information & communication | 2026 |
| SV Developers Ltd | Construction | 2018 |
| SV Mansfield Limited | Real estate | 2022 |
| SVK1 Limited | Real estate | 2026 |
| SW Client Services Limited | Professional & scientific | 2022 |
| Swallow Motor Company Limited | Extraterritorial | 2005 |
| Swallow Taylor Property Developments Limited | Real estate | 2022 |
| Swazz Ltd | Information & communication | 2023 |
| Sweet Dreams Sleep Ltd | Other services | 2023 |
| Sweet Spot & Curry House Limited | Hospitality | 2026 |
| Sweet Sweat Shop Ltd | Wholesale & retail | 2018 |
| Sweet Things (Cakes) Limited | Manufacturing | 2009 |
| Swellen Properties Ltd | Real estate | 2021 |
| Sweya Investments Limited | Financial services | 2026 |
| Swift Bridging Limited | Financial services | 2024 |
| Swyftbuy Ltd | Wholesale & retail | 2024 |
| Sycamor Properties Ltd | Real estate | 2018 |
| Sylvester Court Limited | Real estate | 2016 |
| Sylvia Investments Limited | Financial services | 2023 |
| Symphony Technology Limited | Information & communication | 1996 |
| Synchronising Ltd | Arts & recreation | 2022 |
| Synergy Health Plus Limited | Health & social care | 2011 |
| Synergy Home Development Ltd | Construction | 2026 |
| Synergy Rich Solutions Limited | Hospitality | 1998 |
| Syntax Golf Limited | Other services | 2025 |
| Syphon Ltd | Health & social care | 2021 |
| SYR 82 Limited | Construction | 2022 |
| Syrig Construction Ltd | Construction | 2025 |
| System Assure Ltd | Information & communication | 2017 |
| Systemic Innovation Ltd | Professional & scientific | 2021 |
| Systems Data Integration Consultants Ltd | Information & communication | 2015 |
| Syun Ltd | Professional & scientific | 2020 |
| T & N Wellness Limited | Health & social care | 2012 |
| T C Connect Holdings Limited | Information & communication | 2019 |
| T Food & Wine Limited | Wholesale & retail | 2026 |
| T&D Assets Ltd | Professional & scientific | 2014 |
| T&H Corporation Limited | Health & social care | 2025 |
| T&M Premier Estates Ltd | Real estate | 2023 |
| T&M Property Rental Ltd | Real estate | 2021 |
| T&O Services Ltd | Health & social care | 2015 |
| T. & C. Contractors Limited | Construction | 1997 |
| T. Casillas Ltd | Health & social care | 2009 |
| T.R. GB Investments Limited | Real estate | 2019 |
| TA Surveyors Limited | Professional & scientific | 2025 |
| Taab London Ltd | Manufacturing | 2015 |
| Tabor Flat Management Company Limited | Real estate | 1981 |
| Tactus Lifesciences Limited | Wholesale & retail | 2025 |
| TAD Agency Ltd | Education | 2018 |
| TAG Drinks Limited | Wholesale & retail | 2019 |
| TAG Enterprises (London) Limited | Wholesale & retail | 2024 |
| TAG Group Holdings Limited | Financial services | 2019 |
| Taiga Burger Kitchen Limited | Hospitality | 2021 |
| Tailorbirds Property Services Ltd | Hospitality | 2021 |
| Taki's Estates Limited | Real estate | 2025 |
| Talboys Properties Ltd | Real estate | 2020 |
| Talenbot Recruitment Ltd | Real estate | 2017 |
| Talent Glow Solution Ltd | Information & communication | 2023 |
| TALENT36T Limited | Administrative & support | 2019 |
| Talia Collis Studio Limited | Information & communication | 2023 |
| Talking Counselling Ltd | Health & social care | 2022 |
| Tallawah Housing Limited | Real estate | 2023 |
| Talwar Empire Limited | Real estate | 2023 |
| Tamco International (UK) Ltd | Wholesale & retail | 2025 |
| Tamil Rights Group - UK Ltd | Health & social care | 2024 |
| Tamman Legal Limited | Professional & scientific | 2026 |
| Tana VON Zitzewitz Ltd | Arts & recreation | 2020 |
| Tandev Ltd | Real estate | 2021 |
| Tanish Advisors Limited | Professional & scientific | 2025 |
| Tanishi Medical Services Ltd | Health & social care | 2022 |