| Synergism Ltd | Information & communication | 2023 |
| Synergist Consulting Ltd | Administrative & support | 2018 |
| Synergy ARC Consulting Group Ltd | Professional & scientific | 2023 |
| Synergy Fitness Professionals Limited | Arts & recreation | 2016 |
| Synergy Safety Solutions Ltd | Education | 2019 |
| Synergy VC Ltd | Information & communication | 2024 |
| Synergyx Solutions Limited | Professional & scientific | 2023 |
| Synk Spot Ltd | Information & communication | 2023 |
| Synsera Ltd | Information & communication | 2025 |
| Synski Limited | Professional & scientific | 2009 |
| Syntamatic Digital Ltd. | Information & communication | 2025 |
| Synthea Limited | Wholesale & retail | 2024 |
| Synthesised Ltd | Professional & scientific | 2020 |
| Synthetic Brains Ltd | Information & communication | 2025 |
| Synthlayer Ltd | Information & communication | 2026 |
| Syon Asset Holdings Ltd | Real estate | 2019 |
| Syon Asset Management Ltd | Real estate | 2017 |
| Syon Court Residents Association Limited | Households | 2006 |
| Syon Interiors London Ltd | Professional & scientific | 2018 |
| SYR Properties Ltd | Real estate | 2021 |
| Syracuse Lakes Limited | Information & communication | 2023 |
| SYS Property Company Limited | Real estate | 2022 |
| Sysam Ltd | Manufacturing | 2020 |
| Systech Consulting Ltd | Information & communication | 2017 |
| System Intern Construct Ltd | Construction | 2025 |
| Systems Communication Ltd. | Construction | 2015 |
| Syuita Ltd | Wholesale & retail | 2025 |
| SZ Optics Ltd | Health & social care | 2017 |
| SZ UK Services Limited | Other services | 2019 |
| Szab Ltd | Real estate | 2024 |
| Szah Holdings Ltd | Real estate | 2024 |
| Szalay Services Limited | Administrative & support | 2019 |
| Szan Group Ltd | Professional & scientific | 2019 |
| Szan Technology Ltd | Information & communication | 2024 |
| Szoni Property Services Ltd | Real estate | 2025 |
| T & B Concrete Limited | Construction | 2009 |
| T & Family Ltd. | Professional & scientific | 2023 |
| T & I Aligned Properties Limited | Real estate | 2026 |
| T & T Realty Ltd | Real estate | 2021 |
| T & UP Developers Ltd | Construction | 2013 |
| T & Z Virk Construction Ltd | Construction | 2025 |
| T .A.A.A .Group Limited | Households | 2025 |
| T a Consultancy Limited | Professional & scientific | 2002 |
| T a Motors Engineers Ltd | Wholesale & retail | 2021 |
| T Accountants & Co Ltd | Professional & scientific | 2013 |
| T and J Housing Ltd | Real estate | 2023 |
| T and O Property Ltd | Real estate | 2024 |
| T Brown Print Ltd | Professional & scientific | 2021 |
| T H K Consultants Ltd | Professional & scientific | 2019 |
| T Height Ltd | Real estate | 2024 |
| T J D Holdings Ltd | Real estate | 2017 |
| T JAC Properties Limited | Real estate | 2019 |
| T K Construction & Son's London Limited | Construction | 2016 |
| T K Grant Limited | Construction | 1997 |
| T L Advisors Ltd | Professional & scientific | 2024 |
| T Mahmood Services Limited | Administrative & support | 2022 |
| T N Accessories Ltd | Wholesale & retail | 2014 |
| T Padel Ltd | Arts & recreation | 2024 |
| T SET Ltd | Construction | 2023 |
| T&A Facades Ltd | Construction | 2024 |
| T&C Steel Ltd | Manufacturing | 2023 |
| T&F Autos Ltd | Manufacturing | 2024 |
| T&G Global Ltd | Wholesale & retail | 2014 |
| T&J Cleaning Ltd | Administrative & support | 2018 |
| T&J Electricals (UK) Ltd | Energy | 2015 |
| T&J Plumbing and GAS Ltd | Energy | 2018 |
| T&K Property Group Ltd | Real estate | 2019 |
| T&K World Services Limited | Hospitality | 2018 |
| T&L Legacy Ltd | Financial services | 2026 |
| T&M Legis Ltd | Professional & scientific | 2022 |
| T&R Projects Ltd | Construction | 2025 |
| T&T Tiling Ltd | Construction | 2021 |
| T&Z Universe Ltd | Wholesale & retail | 2026 |
| T-Line UK Ltd | Construction | 2020 |
| T. Visaman & Sons Limited | Construction | 2006 |
| T.C.M Site Construction Ltd | Manufacturing | 2025 |
| T.F.Host Limited | Real estate | 2024 |
| T.G. Boorman Ltd | Construction | 2017 |
| T.H. Limited | | 1989 |
| T.I Digital Solution Ltd | Wholesale & retail | 2021 |
| T.J. Accounting Ltd | Professional & scientific | 1996 |
| T3M Consultancy Ltd | Professional & scientific | 2026 |
| T4 Services Ltd | Administrative & support | 2018 |
| T4 WMT Limited | Wholesale & retail | 2022 |
| TA & AK Limited | Health & social care | 2022 |
| TA PAL Ltd | Administrative & support | 2025 |
| TA Traders (UK) Ltd | Wholesale & retail | 2009 |
| Taah Services Ltd | Administrative & support | 2022 |
| Taar Limited | Wholesale & retail | 2018 |
| Taatas Limited | Wholesale & retail | 2023 |
| Taaz Project Ltd | Construction | 2025 |
| TAB Estate Management Limited | Real estate | 2024 |
| TAB Properties Management Limited | Construction | 2004 |
| Tabish Traders Ltd | Wholesale & retail | 2024 |
| Tabishabi Ltd | Wholesale & retail | 2025 |
| TAC MCR Ltd | Real estate | 2020 |
| Tacooba Limited | Agriculture & fishing | 2025 |
| Tacs Count Ltd | Professional & scientific | 2023 |
| Tadda Limited | Wholesale & retail | 2019 |
| Tadr Limited | Information & communication | 2013 |