| SYN50 Limited | Health & social care | 2019 |
| Synergistic Project Management Solutions Ltd | Professional & scientific | 2023 |
| Synergy FAS Ltd | Construction | 2025 |
| Synergy Fire and Smoke Ltd | Construction | 2025 |
| Synergy Fire Limited | Administrative & support | 2023 |
| Synergy Hire Limited | Administrative & support | 2019 |
| Synergy Wellbeing Ltd | Professional & scientific | 2019 |
| Syntilla Ltd | Manufacturing | 2019 |
| Syrius Consulting Limited | Professional & scientific | 2019 |
| SYS Boost Limited | Information & communication | 2020 |
| System Scaffold Contracts Limited | Construction | 2000 |
| System Scaffolds Limited | Extraterritorial | 2018 |
| Systematic Analysis Ltd | Professional & scientific | 2022 |
| Systems & Change Solutions Ltd | Professional & scientific | 2026 |
| Systemwise Installations Limited | Administrative & support | 2025 |
| Syte Architectural Glazing (UK) Limited | Extraterritorial | 2008 |
| Syte Architectural Glazing Limited | Other services | 1995 |
| Szasz I.T. Consultants Limited | Information & communication | 1998 |
| Szmodics & Co Limited | Real estate | 2026 |
| T & E Autos Ltd | Wholesale & retail | 2016 |
| T & I Steel Limited | Construction | 2019 |
| T & L Builders Ltd | Construction | 2025 |
| T & L Electrics Ltd | Construction | 2026 |
| T & L Painting and Decorating Services Limited | Construction | 2018 |
| T & R Noakes Services Limited | Construction | 2003 |
| T B Motors Bedford Ltd | Wholesale & retail | 2023 |
| T C Day Contractors Limited | Construction | 2015 |
| T C Newton and Sons (Contracting) Ltd | Construction | 2011 |
| T C Newton and Sons (Developments) Ltd | Construction | 2006 |
| T C Newton and Sons (Holdings) Ltd | Financial services | 2011 |
| T C Ventilation Ltd | Manufacturing | 2013 |
| T E Flooring Limited | Construction | 2025 |
| T F Equine Limited | Arts & recreation | 2018 |
| T Farmer & Company Limited | Hospitality | 2018 |
| T H H Centre Ltd | Wholesale & retail | 2018 |
| T H H Global Ltd | Wholesale & retail | 2023 |
| T J Edwards & Sons Ltd | Professional & scientific | 2016 |
| T J Young Limited | Agriculture & fishing | 2008 |
| T M Civils Ltd | Construction | 2018 |
| T M Freeman Limited | Construction | 2003 |
| T N Property Developments Ltd | Real estate | 2021 |
| T R Skiphire Limited | Water & waste | 2003 |
| T Robinson Heating & GAS Limited | Construction | 2017 |
| T S Grill Ltd | Hospitality | 2022 |
| T S Tractor Spares & Repairs Ltd | Agriculture & fishing | 2025 |
| T&J Beaumont's Limited | Real estate | 2023 |
| T&J Cosmetics Ltd | Wholesale & retail | 2018 |
| T&T Cornerstone Properties Ltd | Real estate | 2026 |
| T'Z Desserts Bedford Ltd | Hospitality | 2026 |
| T-Evolve Limited | Professional & scientific | 2023 |
| T-Pharm Group Limited | Real estate | 2021 |
| T-Seven & Associates Ltd | Professional & scientific | 2024 |
| T-Speed Performance Ltd | Wholesale & retail | 2024 |
| T. Filipczak Ltd | Financial services | 2021 |
| T.Ali Properties Ltd | Real estate | 2024 |
| T.Archive Ltd | Wholesale & retail | 2025 |
| T.B.L Building Services Limited | Construction | 2021 |
| T.C.F Excavating Ltd | Other services | 2021 |
| T.F. Holdings Limited | Real estate | 1970 |
| T.I Bespoke Consultancy Ltd | Professional & scientific | 2025 |
| T.J. OP Ltd | Construction | 2024 |
| T.J.D. Trade Limited | Construction | 2003 |
| T.L. Rail Ltd | Construction | 2014 |
| T.L.X. (Electrical) Limited | Wholesale & retail | 1994 |
| T.M.E. Fabrications Limited | Construction | 1997 |
| T.P Long Plumbing & Heating Ltd | Construction | 2025 |
| T.R.I.M. Property Investments Ltd | Real estate | 2024 |
| T.S Awan & Sons Ltd | Wholesale & retail | 2026 |
| T.Wren Consulting Ltd | Other services | 2019 |
| T10 Enterprise Ltd | Education | 2015 |
| TAE (UK) Limited | Administrative & support | 2002 |
| Taelo Enterprise Ltd | Health & social care | 2013 |
| Taffmad Logistics Limited | Transport & logistics | 2026 |
| Tafmad Limited | Transport & logistics | 2019 |
| Taftech Trade Ltd | Wholesale & retail | 2023 |
| TAG Live Limited | Arts & recreation | 2020 |
| Tagico Ltd | Wholesale & retail | 2018 |
| Tahery Limited | Education | 2017 |
| Tailored Construction Limited | Construction | 2026 |
| Tailoring Services for Children & Families Limited | Health & social care | 2016 |
| Taimur Investments Ltd | Real estate | 2021 |
| Tainmore Properties Limited | Real estate | 2022 |
| Tait Electrical Ltd | Manufacturing | 2025 |
| Take Charge Ltd | Administrative & support | 2026 |
| Take Flight Productions Ltd | Professional & scientific | 2017 |
| Take to the Air Ltd | Arts & recreation | 2017 |
| Takescrapcar Limited | Wholesale & retail | 2023 |
| Takeshape Limited | Professional & scientific | 1999 |
| Taketwoforyou Ltd | Health & social care | 2026 |
| Tala Life Limited | Information & communication | 2024 |
| Talbots Plumbing and Heating Services Ltd | Construction | 2017 |
| Talboys Drylining Ltd | Construction | 2019 |
| Talent Artistic Group Limited | Arts & recreation | 2013 |
| Talent Group Services Limited | Administrative & support | 2023 |
| Talentaxis Consulting Ltd | Administrative & support | 2025 |
| Talisman Innovations Limited | Information & communication | 2012 |
| Taluka Properties Ltd | Real estate | 2026 |
| Talwinder Kumar Ltd | Construction | 2024 |
| TAM Entertainment Limited | Information & communication | 2024 |
| Tamar Brickhill Developments Limited | Extraterritorial | 1971 |