| Swiss Aring Solutions Ltd | Real estate | 2015 |
| Swissvac Limited | Extraterritorial | 2017 |
| Switch Q Services Limited | | 2005 |
| SWN Limited | Wholesale & retail | 1958 |
| SWP Investments Limited | Administrative & support | 2006 |
| Swvan Ltd | Wholesale & retail | 2024 |
| Swyft Couriers Ltd | Hospitality | 2024 |
| SY Couriers Limited | Transport & logistics | 2004 |
| SYA Trading Limited | Extraterritorial | 2020 |
| Syan Constructions Ltd | Construction | 2019 |
| Sycamore Close Borrowash Management Company Limited | Real estate | 2015 |
| Sycamore Court Management Company Limited | Households | 1994 |
| Sycamore Musicking Ltd | Information & communication | 2025 |
| Sycamore Park (Lacewood Close) Management Company Limited | Other services | 2019 |
| Sydney Bradley Limited | Real estate | 1952 |
| Syed Rizvi Services Ltd | Information & communication | 2024 |
| SYL Trading Limited | Extraterritorial | 2020 |
| Sylvan Ridge Ltd | Agriculture & fishing | 2026 |
| Symbalis Ltd | Information & communication | 2019 |
| Symbel Properties Limited | Real estate | 2018 |
| Symbol Integrated Services Ltd | Health & social care | 2017 |
| Symonds Ventures Limited | Professional & scientific | 2026 |
| Symtel Ltd | Information & communication | 2025 |
| Syncd Ltd | Information & communication | 2020 |
| Synced Talent Limited | Professional & scientific | 2024 |
| Synergetic Health Ltd | Health & social care | 2018 |
| Synergit Group Limited | Administrative & support | 2023 |
| Synergy Health Managed Services Limited | Health & social care | 2013 |
| Synergy Medical Solutions Limited | Health & social care | 2011 |
| Synergy Procurement Group Ltd | Wholesale & retail | 2023 |
| Synergy.Net Limited | Information & communication | 1997 |
| Synko 88 Limited | Wholesale & retail | 2015 |
| Synkrony Limited | Wholesale & retail | 2004 |
| Syntax Consultancy Limited | Administrative & support | 1987 |
| Syntegon Technology Limited | Manufacturing | 1991 |
| Synthosys Limited | Professional & scientific | 2024 |
| Syskaa Limited | Real estate | 2024 |
| System Scaffolding (Midlands) Ltd | Construction | 2013 |
| Systemicsoul Ltd | Education | 2025 |
| Systems AG Ltd | Professional & scientific | 2019 |
| Systems Engineering for Service Ltd | Professional & scientific | 2022 |
| Systemsecurex Limited | Professional & scientific | 2026 |
| Systmcpr Limited | Information & communication | 2022 |
| Systram Consultancy Limited | Real estate | 2009 |
| Szekeramd Ltd | Real estate | 2026 |
| T & a Haulage Ltd | Transport & logistics | 2021 |
| T & P Financial Services Limited | Financial services | 2026 |
| T & Z Haulage Ltd | Transport & logistics | 2022 |
| T Basi Analysis Limited | Information & communication | 2013 |
| T Birkinshaw Properties Limited | Real estate | 2023 |
| T Clarke Plumbing & Heating Ltd | Construction | 2015 |
| T Dansie Limited | Financial services | 2006 |
| T G Pipelines Limited | Energy | 2021 |
| T H Grounds Maintenance Ltd | Administrative & support | 2023 |
| T H Shah & Co Ltd | Professional & scientific | 2024 |
| T Jones Fabrications (Riddings) Limited | Manufacturing | 2011 |
| T Jones Fabrications Holdings Ltd | Financial services | 2021 |
| T Kaur Collection Limited | Wholesale & retail | 2024 |
| T Lowe Engineering Solutions Ltd | Professional & scientific | 2019 |
| T Nicholson Electrical Ltd | Construction | 2025 |
| T Nicholson Investments Ltd | Real estate | 2024 |
| T Shirts Online Ltd | Wholesale & retail | 2020 |
| T T Flooring Ltd | Construction | 2011 |
| T T S Construction Ltd | Construction | 2003 |
| T&A Family Investment Limited | Real estate | 2022 |
| T&G Woodware Ltd | Wholesale & retail | 1975 |
| T&H Ford Freight Services LLP | | 2026 |
| T&S Derby Properties Limited | Real estate | 2022 |
| T&T Gidda Limited | Transport & logistics | 2026 |
| T&W Automotive Limited | Wholesale & retail | 2025 |
| T. Klofas Ltd | Transport & logistics | 2015 |
| T.C.N. Plant Services Ltd | Manufacturing | 2022 |
| T.Fenton Limited | Financial services | 2026 |
| T.H Pest Control Ltd | Professional & scientific | 2021 |
| T.I.M. Solutions Limited | Information & communication | 2012 |
| T.J. O Connor Group Limited | Professional & scientific | 2009 |
| T.J.A.S Joinery Manufacturers Limited | Manufacturing | 2003 |
| T.Krupinski Ltd | Wholesale & retail | 2017 |
| T.L House Cleaning Ltd | Administrative & support | 2022 |
| T.L. Darby (Holdings) Limited | Professional & scientific | 1974 |
| T.M-Weir Property Ltd | Real estate | 2022 |
| T.P.O'Leary Building Services Ltd | Construction | 2022 |
| T.S.L Accounts Ltd | Professional & scientific | 2025 |
| T2K Ltd | Transport & logistics | 2025 |
| T2K Network Ltd | Wholesale & retail | 2026 |
| T3 Network Solutions Limited | Information & communication | 2006 |
| T4TUTOR Limited | Education | 2025 |
| T89 Designs Limited | Professional & scientific | 2013 |
| T8STY Fusion Ltd | Hospitality | 2025 |
| TA Medical Healthcare Limited | Administrative & support | 2023 |
| Taadpol Limited | Professional & scientific | 2017 |
| Tabar Properties Ltd | Real estate | 2021 |
| Tabigail Private Ltd. | Other services | 2017 |
| Tablk Composite Installations Ltd | Manufacturing | 2019 |
| Tactical Energy Systems Ltd | Construction | 2024 |
| Tactical Wellbeing Ltd | Education | 2022 |
| Tactile Games Limited | Information & communication | 2018 |
| TAD UK Steel Limited | Professional & scientific | 2014 |
| Tadc Sport Limited | Arts & recreation | 2026 |
| Taflam Group Limited | Wholesale & retail | 2025 |