| Sync. HQ Ltd | Financial services | 2019 |
| Synergy (Beaconsfield) Limited | Real estate | 2020 |
| Synergy Assessing Ltd | Education | 2024 |
| Synergy Elite Ltd | Arts & recreation | 2024 |
| Synergy Fundraising Ltd | Other services | 2018 |
| Synergy Industrial Solutions Limited | Construction | 2024 |
| Synergy Investigative Solutions Limited | Administrative & support | 2021 |
| Synergy Personnel (Manchester) Limited | Administrative & support | 2025 |
| Synergy Personnel Limited | Administrative & support | 2016 |
| Synergy Plumbing, Heating & Renewables Ltd | Construction | 2021 |
| Synergy Property & Construction Group Limited | Real estate | 2021 |
| Synergy Safety UK Limited | Public administration | 2020 |
| Synergy Security Services Limited | Administrative & support | 2019 |
| Synergy-Uk Limited | Other services | 2022 |
| Synergyfiit Limited | Wholesale & retail | 2023 |
| Synexa Group Limited | Information & communication | 2026 |
| Synor House Management Limited | Households | 2002 |
| Syntassein Ltd | Information & communication | 2026 |
| Syntrend Corporation Ltd | Manufacturing | 2025 |
| Syos Aerospace UK Limited | Professional & scientific | 2023 |
| System Insight Holdings Ltd | Professional & scientific | 2012 |
| System Insight Limited | Professional & scientific | 2012 |
| Systematic Bookkeeping Services Ltd | Professional & scientific | 2013 |
| Systematised Solutions Limited | Information & communication | 2020 |
| Systems Safety Engineering Ltd | Professional & scientific | 2012 |
| Sywell Healthcare Ltd | Health & social care | 2022 |
| Sywell Properties Limited | Real estate | 2023 |
| Szabi the HUN Ltd | Health & social care | 2020 |
| Szoke a Ltd | Construction | 2020 |
| T & a Southampton Limited | Transport & logistics | 2025 |
| T & D Garran Limited | Health & social care | 2010 |
| T & K Enterprises Limited | Wholesale & retail | 2013 |
| T & K Property Developments Ltd | Real estate | 2018 |
| T & L Redman Ltd | Professional & scientific | 2009 |
| T & S & H Ltd | Real estate | 2020 |
| T & T Healthcare Solutions Limited | Health & social care | 2025 |
| T & T Lets Clean Limited | Administrative & support | 2018 |
| T & W Electrical (South Coast) Limited | Construction | 2012 |
| T & W Electrical Holdings (South Coast) Limited | Construction | 2012 |
| T Air Ltd | Construction | 2020 |
| T and M Cable Services Limited | Construction | 1994 |
| T B Sports Agent Limited | Professional & scientific | 2022 |
| T Clark & SON Limited | Real estate | 1931 |
| T D Gregory Office Services Limited | Professional & scientific | 2003 |
| T D M Electric Limited | Manufacturing | 2022 |
| T F Hairstyle Limited | Other services | 2019 |
| T J Hill Construction Ltd | Construction | 2020 |
| T LAI Property Management Limited | Real estate | 2025 |
| T M Sparkle Clean Limited | Administrative & support | 2025 |
| T Mcveigh Mortgages Limited | Financial services | 2004 |
| T Moran Construction Management Limited | Construction | 2018 |
| T R Motor Company Southampton Ltd | Wholesale & retail | 2026 |
| T Smith Limited | Manufacturing | 2012 |
| T Sparrow Ltd | Construction | 2021 |
| T T Mortgages UK Ltd | Financial services | 2012 |
| T W Clark Holdings Limited | Financial services | 2005 |
| T Willmott Limited | Administrative & support | 2019 |
| T&A Lettings Ltd | Real estate | 2025 |
| T&A Prime Ltd | Wholesale & retail | 2026 |
| T&B Renovations Limited | Construction | 2024 |
| T&Ecc Events Limited | Hospitality | 2006 |
| T&S Architectural Ltd | Wholesale & retail | 2025 |
| T&S/Uk Ltd | Hospitality | 2020 |
| T&T Payroll and Audit Ltd | Professional & scientific | 2026 |
| T&T Squared Property Solutions Limited | Real estate | 2025 |
| T&V Textiles Ltd | Extraterritorial | 2017 |
| T&W Investments Limited | Real estate | 2006 |
| T-Jahc Limited | Wholesale & retail | 2025 |
| T-Mec (Thompson Marine Engineering Consultancy & Services) Ltd | Professional & scientific | 2013 |
| T-Rodger Ltd | Transport & logistics | 2018 |
| T. Darby (Electrical) Limited | Construction | 1998 |
| T.A. Fish (Builders) Limited | Construction | 1962 |
| T.A.C.K.A Ltd | Construction | 2016 |
| T.B. Musicals Limited | Arts & recreation | 2002 |
| T.Hashemi Limited | Wholesale & retail | 2023 |
| T.J. Hayes Roofing Limited | Construction | 2012 |
| T.J. Mitcheson Ltd | Construction | 2003 |
| T.J.M. Groundwork and Building Contractors Ltd. | Construction | 2001 |
| T.O.P. 1 Office Ltd | Administrative & support | 2016 |
| T.P.O. Projects Limited | Construction | 2024 |
| T.P.O. Property Services Limited | Extraterritorial | 2026 |
| T.R.M. Tisch Limited | Hospitality | 1991 |
| T.Rook Windows & Doors Ltd | Construction | 2026 |
| T.S. Marine Limited | Manufacturing | 1998 |
| T.Webber Bricklaying & Building Services Limited | Construction | 2015 |
| T2 Growth Partners Limited | Financial services | 2022 |
| T3A Properties Ltd | Real estate | 2024 |
| T4 Growth Capital Limited | Financial services | 2022 |
| TA Vehicle Repairs Ltd | Wholesale & retail | 2023 |
| TAB Weld Limited | Other services | 2021 |
| Tabletop Tombola Ltd | Arts & recreation | 2023 |
| Tabono Properties Ltd | Real estate | 2021 |
| Tachmonite Limited | Financial services | 2025 |
| Tactical Accountancy Limited | Wholesale & retail | 2019 |
| Tactical Support Holdings Ltd | Financial services | 2022 |
| Tactical Support Services Limited | Wholesale & retail | 2015 |
| TAD Furniture Ltd | Wholesale & retail | 2025 |
| TAE Consultancy Ltd | Wholesale & retail | 2015 |
| Taffy's Ltd | Health & social care | 2018 |
| Taftpoint Ltd | Professional & scientific | 2021 |