| Stronglift Ltd | Wholesale & retail | 2025 |
| Strongman Delivery Ltd | Transport & logistics | 2025 |
| Structural Solutions Ltd | Professional & scientific | 2020 |
| STS Conservation Limited | Extraterritorial | 2013 |
| STS General Maintenance FM Limited | Construction | 2013 |
| STS Lightning Protection Services Limited | Construction | 2013 |
| STS Restoration Limited | Construction | 2013 |
| Stuart James Hall Ltd | Education | 2024 |
| Stubb House Farms Limited | Agriculture & fishing | 2019 |
| Stubb Legal Limited | Education | 2001 |
| Student Loans Company Limited | Financial services | 1989 |
| Studio Aero Ltd | Information & communication | 2021 |
| Studio Aesthetic Ltd | Other services | 2024 |
| Studio Harp Ltd | Information & communication | 2024 |
| Studio Monarch Limited | Information & communication | 2025 |
| Studiotypes Ltd | Administrative & support | 2016 |
| STX Subsea Ltd | Professional & scientific | 2023 |
| SUB Station Darlington Ltd | Hospitality | 2017 |
| Subscription Labs Limited | Wholesale & retail | 2014 |
| Subsea and Hydraulics Ltd | Professional & scientific | 2015 |
| Subsea Innovation Limited | Manufacturing | 1995 |
| Subway Starbeck Ltd | Hospitality | 2010 |
| SUE Pattison Consulting Ltd | Education | 2015 |
| Suehoo Limited | Professional & scientific | 2015 |
| Sugarcube Occupational Health Ltd | Administrative & support | 2023 |
| Summer Anne Bridal Limited | Wholesale & retail | 2022 |
| Summerfield Home Finance Ltd | Financial services | 2026 |
| Summerhouse Development Limited | Construction | 2011 |
| Sums Anaesthesia Limited | Real estate | 2015 |
| Sunanda EYE Care Ltd | Health & social care | 2020 |
| Sundial Lettings Limited | Real estate | 2023 |
| Sunflower Travel Ltd | Administrative & support | 2025 |
| Sunkissed Tanning Services Limited | Other services | 2022 |
| Sunset Sessions Ltd | Hospitality | 2019 |
| Sunshine Sensory Ltd | Education | 2018 |
| Suntrack Energy Solutions Ltd | Construction | 2025 |
| Supply Chain Warehouse Limited | Wholesale & retail | 2015 |
| Surge Accounting Ltd | Professional & scientific | 2022 |
| Survey and Installation Limited | Construction | 2023 |
| Surveyexpert Limited | Real estate | 1995 |
| Sussex Tile and Stone Ltd | Construction | 2012 |
| Sustainable Timber Ltd | Agriculture & fishing | 2016 |
| Sustainably Bridal Ltd | Wholesale & retail | 2024 |
| SVR Lettings Ltd | Real estate | 2017 |
| SVS Technologies Ltd | Information & communication | 2023 |
| SW & Associates Ltd | Professional & scientific | 2013 |
| SW & SW Properties Ltd | Real estate | 2026 |
| SW Access Painting Limited | Construction | 2023 |
| SW Lunnon Construction Ltd | Construction | 2018 |
| SW Pilates Limited | Arts & recreation | 2014 |
| Swafe Energy Ltd | Professional & scientific | 2025 |
| Swaledale Holiday Cottages Ltd | Hospitality | 2022 |
| Swan KEE Limited | Financial services | 2012 |
| Swaran Foods Limited | Hospitality | 2025 |
| Sweet Escape Ltd | Wholesale & retail | 2019 |
| Swiftflex Ltd | Transport & logistics | 2025 |
| Swiftpass Driver Trainer Limited | Education | 2018 |
| SWINMADCO58 Limited | Financial services | 2020 |
| Swoop Limited | Other services | 2002 |
| Sylvan Glade SPV Ltd | Construction | 2024 |
| Synchronicity Care Ltd. | Health & social care | 2015 |
| Synergy Lifting Ltd | Administrative & support | 2014 |
| Synk Events Limited | Other services | 2009 |
| Syntho Silicon Ltd | Professional & scientific | 2023 |
| Sysbro Solutions LLP | | 2024 |
| Sysrol Ltd | Transport & logistics | 2023 |
| T & E Property NE Ltd | Real estate | 2026 |
| T & G Training Limited | Education | 2011 |
| T & K Building Maintenance Ltd | Construction | 2023 |
| T & M Business Services Ltd | Administrative & support | 2013 |
| T & M Weaver Limited | Construction | 2005 |
| T & T Business Services Limited | Administrative & support | 2015 |
| T a Minimarket Ltd | Wholesale & retail | 2022 |
| T B W R Property Investments Ltd | Real estate | 2025 |
| T C Williams Roofing and Plastering Ltd | Construction | 2020 |
| T Crang Taxi Co Ltd | Extraterritorial | 2017 |
| T H Vickers Limited | Real estate | 2006 |
| T J Landscapes Ltd | Administrative & support | 2018 |
| T R M Marketing Limited | Administrative & support | 1998 |
| T W R Property Investments Ltd | Real estate | 2025 |
| T&T Rooflines (Commercial) Ltd | Construction | 2022 |
| T. M. Ward (Darlington) Limited | Construction | 1992 |
| T.D. Bell Ltd | Other services | 2001 |
| T.M. Ward (Contracts) Limited | Extraterritorial | 2001 |
| T23 Trading Ltd | Wholesale & retail | 2025 |
| TA Hallet Logistics Ltd | Transport & logistics | 2025 |
| Tackle Hub Ltd | Wholesale & retail | 2025 |
| Tagvee Horizons Limited | Real estate | 2021 |
| Tahira Batool Dreamz Ltd | Wholesale & retail | 2025 |
| Take Root BIO Limited | Agriculture & fishing | 2022 |
| Takes IT Away UK Ltd | Water & waste | 2026 |
| Talon Electrical North East Limited | Construction | 2010 |
| Talulakids Ltd | Wholesale & retail | 2025 |
| TAM Transport Logistic Ltd | Wholesale & retail | 2023 |
| TAN Gagz Ltd | Wholesale & retail | 2018 |
| Tanbul Ltd | Hospitality | 2020 |
| Tancream Limited | Other services | 2014 |
| Tandridge Court Management Company Limited(The) | Households | 1981 |
| Tanning Express Ltd | Manufacturing | 2023 |
| Tape Deck Ltd | Information & communication | 2023 |