| Studio Desreè Ltd | Wholesale & retail | 2024 |
| Studio Three Graphics Ltd | Information & communication | 2015 |
| Stuntworks Ltd | Information & communication | 2012 |
| Stusinclair Limited | Professional & scientific | 2012 |
| Stuzanne Limited | Extraterritorial | 2015 |
| Success With Speech Therapy Ltd | Health & social care | 2024 |
| Sugoya Ltd | Professional & scientific | 2025 |
| Sun Chinese Ltd | Hospitality | 2019 |
| Sun City Partnership Limited | Other services | 2023 |
| Sun Street Properties Limited | Real estate | 2022 |
| Sunday Social Collective Ltd | Professional & scientific | 2024 |
| SUNNY2019 Ltd | Transport & logistics | 2026 |
| Sunshine Travel Limited | Administrative & support | 2022 |
| Super Foods Express Ltd | Wholesale & retail | 2019 |
| Supermassive Limited | Professional & scientific | 2014 |
| Supracycling Global Limited | Manufacturing | 2021 |
| Sure Thing Media Ltd | Information & communication | 2023 |
| Surface Maintain Ltd | Manufacturing | 2021 |
| Surveyplus Virtual Move Consultancy Limited | Information & communication | 2020 |
| SVA Estates Ltd | Real estate | 2025 |
| SVC Consultants Limited | Professional & scientific | 2026 |
| Swandor Limited | Professional & scientific | 2023 |
| SWB Contractors Ltd | Construction | 2020 |
| SWB Group Holdings Ltd | Financial services | 2021 |
| Sweetfoot Ltd | Manufacturing | 2026 |
| Swift Auto Repair Centre Limited | Wholesale & retail | 2024 |
| Swiftstyle Technologies Ltd | Wholesale & retail | 2026 |
| Swimsafe Swimwear Ltd | Wholesale & retail | 2025 |
| Swing Supply Limited | Wholesale & retail | 2022 |
| Sync on Green Limited | Professional & scientific | 2011 |
| Synergy Works Group Limited | Professional & scientific | 2025 |
| Syntheks Ltd | Information & communication | 2023 |
| Systems Engineering (Consultants) Limited | Information & communication | 1983 |
| Syty Hospitality Limited | Hospitality | 2026 |
| Syty Limited | Hospitality | 2026 |
| SZ Residences Limited | Real estate | 2026 |
| T & D Glazing and Installation Limited | Construction | 2003 |
| T Build and Renovate Ltd | Construction | 2015 |
| T J Lewis Building Ltd | Construction | 2019 |
| T K Painters Limited | Construction | 2018 |
| T Mackenzie Mechanical Limited | Agriculture & fishing | 2016 |
| T R Pallets Limited | Wholesale & retail | 2005 |
| T R R G Services Ltd | Construction | 2018 |
| T&A Street Food Ltd | Hospitality | 2026 |
| T&J Story Street Ltd | Construction | 2021 |
| T&M Maintenance Ltd | Construction | 2024 |
| T&Tabu Limited | Wholesale & retail | 2023 |
| T. Windows Limited | Construction | 2006 |
| T.Bullen Sales Ltd | Wholesale & retail | 2024 |
| TAD Recruitment Ltd | Administrative & support | 2017 |
| Talent Access CIC | Administrative & support | 2024 |
| Talent Force HR Ltd | Administrative & support | 2024 |
| Talum Barber Ltd | Other services | 2020 |
| Tamam London Ltd | Professional & scientific | 2025 |
| Tankisi Properties Limited | Real estate | 2023 |
| Tapitt Ltd | Other services | 2020 |
| TARGET7 IT Solutions Limited | Information & communication | 2016 |
| Taste 2025 Limited | Hospitality | 2025 |
| Taxes With Alex Ltd | Professional & scientific | 2022 |
| Taylermade Developments Limited | Construction | 2021 |
| TC Tech Solutions Limited | Information & communication | 2019 |
| Tcon Paving Ltd | Construction | 2017 |
| Tdlr Properties Limited | Real estate | 2018 |
| TDM Building Limited | Construction | 2025 |
| TE Fulcrum Ltd | Professional & scientific | 2016 |
| TE HA9 Ltd | Hospitality | 2018 |
| Team Fleet TV Ltd | Arts & recreation | 2020 |
| Team of Angels Ltd | Transport & logistics | 2022 |
| TEBE68 Ltd | Hospitality | 2024 |
| Tech SP Solutions Ltd | Information & communication | 2025 |
| Techamor Ltd | Information & communication | 2024 |
| Techlove Lobby Limited | Education | 2016 |
| Techmiracle Systems Ltd | Administrative & support | 2024 |
| Technitronic Limited | Other services | 2014 |
| Techunreal Ltd | Information & communication | 2022 |
| TEE Two Limited | Information & communication | 2001 |
| Teknicheian Limited | Professional & scientific | 2020 |
| Telsim Ltd | Extraterritorial | 2025 |
| Teneo Translations UK Ltd | Professional & scientific | 2012 |
| Tenimic Limited | Real estate | 2011 |
| Terra Nostra Cleveland Ltd | Hospitality | 2025 |
| Terra Nostra Waterloo Ltd | Hospitality | 2024 |
| Terra UK Trading Limited | Wholesale & retail | 2021 |
| Terron Plant Limited | Administrative & support | 2026 |
| Teviot Estate Developments LLP | | 2020 |
| TGS Security Limited | Construction | 2019 |
| Thai Express Franchising Limited | Wholesale & retail | 2012 |
| Thai Express Lakeside Limited | Hospitality | 2013 |
| Thai Express UK Limited | Hospitality | 2016 |
| That Heating Company Ltd | Construction | 2013 |
| THE Accommodation People Limited | Real estate | 2020 |
| THE Best Kebab Willesden Ltd | Hospitality | 2022 |
| THE Birches Management Company (Waltham Abbey) Limited | Other services | 2016 |
| THE Bluum Group Ltd | Construction | 2020 |
| THE Boiler Geek London Limited | Construction | 2024 |
| THE Brand Language Studio Ltd | Professional & scientific | 2014 |
| THE Calendar Group Limited | Professional & scientific | 1996 |
| THE Capacity Group Ltd | Real estate | 2002 |
| THE Chase Hotel Limited | Hospitality | 2024 |
| THE Cleaner's Crew Ltd | Administrative & support | 2025 |