| Stratton Place Residents Company Limited | Administrative & support | 1996 |
| Stuart James Limited | Construction | 2000 |
| Stubbs Wood Residents Association Limited | Other services | 1988 |
| Studio 8 Entertainment Ltd | Information & communication | 2020 |
| STUNTS2SCREEN Ltd. | Arts & recreation | 2014 |
| Sturman Investments Limited | Real estate | 2006 |
| Style Happy Ltd. | Other services | 2015 |
| Style in My City Ltd | Administrative & support | 2011 |
| Sucking Diesel Productions Limited | Information & communication | 2022 |
| SUE Collins Associates Ltd | Professional & scientific | 2010 |
| SUE Tate Consulting Limited | Professional & scientific | 2010 |
| SUE Walker Ltd | Health & social care | 2015 |
| Suerte Properties Limited | Real estate | 2013 |
| Sumbiz Investments Ltd | Real estate | 2024 |
| Summit Healthcare Holdings Limited | Financial services | 2026 |
| Sunshine Consulting Ltd | Information & communication | 2015 |
| Sunsoa IT Solutions Limited | Information & communication | 2011 |
| Suntech Medical Group Limited | Professional & scientific | 2000 |
| Super Subbies Limited | Construction | 2013 |
| Supercar Driver Training Ltd | Wholesale & retail | 2024 |
| Superior Garment Care Ltd | Other services | 2015 |
| Supreme Bakers UK Limited | Hospitality | 2015 |
| Suresh Solutions Ltd | Information & communication | 2024 |
| Susana Oliveira Smile Ltd | Health & social care | 2022 |
| Sustain Consulting Ltd | Professional & scientific | 2021 |
| Susthiraa Homes PVT Ltd | Real estate | 2025 |
| Suvarna Services Limited | Information & communication | 2025 |
| Suyoga Sadhana Limited | Other services | 2022 |
| Svrr Consultancy Limited | Information & communication | 2012 |
| Svsa Group Ltd | Hospitality | 2025 |
| SW Management Accountants Limited | Professional & scientific | 2010 |
| Swame Limited | Wholesale & retail | 2017 |
| Swann Estates Ltd | Administrative & support | 2025 |
| Swart Evaluation Ltd | Professional & scientific | 2023 |
| Sweepmate Ltd | Information & communication | 2021 |
| Swethari Private Limited | Information & communication | 2025 |
| Swyzo Ltd | Wholesale & retail | 2022 |
| Syara Services Ltd | Administrative & support | 2025 |
| Synctrix Ltd | Professional & scientific | 2015 |
| Synergetics Systems Ltd | Wholesale & retail | 2021 |
| Systematics Software Limited | Information & communication | 2012 |
| Systemteq Limited | Manufacturing | 1988 |
| T Clark Aviation LLP | | 2006 |
| T.P.R. Mechanical Services Limited | Construction | 1994 |
| T1 Strategies Ltd | Professional & scientific | 2023 |
| Tailor Business Services Limited | Professional & scientific | 2014 |
| Tailwags Dog Walking Ltd | Agriculture & fishing | 2022 |
| Talbot Owners' Club Ltd | Arts & recreation | 2003 |
| Talkback-Uk Ltd. | Health & social care | 2001 |
| Talking FOX Limited | Professional & scientific | 2021 |
| Talking Toolbox Speech and Language Therapy Ltd | Health & social care | 2022 |
| Tallbuild Limited | Professional & scientific | 1912 |
| Talos Construction Ltd | Construction | 2006 |
| Tanda Legacy Ltd | Hospitality | 2025 |
| Tantape Limited | Real estate | 1984 |
| Tara Studios (Ireland) Limited | Professional & scientific | 2020 |
| Tasty Plant Sales Limited | Wholesale & retail | 1999 |
| Tatvamasi Solutions Limited | Information & communication | 2026 |
| Tax Relief Experts Limited | Professional & scientific | 2023 |
| Taxon Ltd | Health & social care | 2016 |
| Taylor & Mustoe Consultancy Ltd | Professional & scientific | 2021 |
| Taylor Made Therapies Limited | Wholesale & retail | 2015 |
| Tazeen Limited | Information & communication | 2021 |
| TD Decorating Services Ltd | Construction | 2018 |
| TD2C Ltd | Other services | 2025 |
| TDM Ic-Disc UK Limited | Administrative & support | 2025 |
| Teach IT CIC | Education | 2020 |
| Teal Brands Limited | Wholesale & retail | 2018 |
| Teal Group Holdings Limited | Professional & scientific | 2017 |
| Teal Property Holdings Limited | Real estate | 2016 |
| Teal Sourcing Limited | Extraterritorial | 2015 |
| Team Eques Limited | Other services | 2020 |
| Team R S Judo Ltd | Education | 2019 |
| Team Versatiles Soft Solutions Ltd | Information & communication | 2014 |
| Techlytics Solutions Limited | Wholesale & retail | 2020 |
| Technical Link Limited | Administrative & support | 1991 |
| Technobuffs Limited | Transport & logistics | 2010 |
| Technobuffs Solutions Limited | Information & communication | 2025 |
| Technology Imex Limited | Professional & scientific | 1997 |
| Teepun Limited | Professional & scientific | 2024 |
| Telangana Jagruthi United Kingdom | Health & social care | 2015 |
| Telix Pharmaceuticals (UK) Limited | Manufacturing | 2017 |
| Telleroo Limited | Information & communication | 2016 |
| Temple Complete Building Limited | Construction | 2012 |
| TEN Sixty Four Limited | Other services | 2025 |
| Tend Trust | Other services | 2005 |
| Tendercure Ltd | Information & communication | 2026 |
| Tenland Limited | Administrative & support | 2005 |
| Tenland Properties Ltd | Real estate | 2019 |
| Terence Trustram Ltd | Manufacturing | 2013 |
| Terrabyte Analytics Limited | Information & communication | 2025 |
| Terriers Farm Limited | Real estate | 1950 |
| Tetr Limited | Education | 2024 |
| Tetson Global Consumer Ltd | Wholesale & retail | 2023 |
| Texo Limited | Professional & scientific | 2009 |
| TFX Group Limited | Manufacturing | 1993 |
| Tgjdr Limited | Real estate | 2026 |
| TGW Festivals Limited | Wholesale & retail | 2024 |
| Thai Grace Massage & Wellness Limited | Other services | 2026 |
| Thames Boat Charters Limited | Transport & logistics | 2006 |