| THE Smokin' ELK Limited | Other services | 2020 |
| THE Society of Sports Therapists | Other services | 2002 |
| THE Southampton Magazine Ltd | Public administration | 2026 |
| THE Southern Co-Operative Pension Trustee Limited | Professional & scientific | 2016 |
| THE Southsea (Peks) Property Company Ltd | Real estate | 2020 |
| THE Southsea EAR Clinic Ltd | Health & social care | 2021 |
| THE Southsea Skatepark Company Limited | Arts & recreation | 2008 |
| THE Spiritual Sanctuary Ltd | Other services | 2020 |
| THE SSH Group Ltd | Administrative & support | 2016 |
| THE Stables Management Company (Netley) Limited | Households | 2020 |
| THE Star & Garter Goodwood Limited | Hospitality | 2026 |
| THE Story IS Everything Limited | Information & communication | 2018 |
| THE Studio (Southern) Ltd | Other services | 2025 |
| THE Studios Management Company Limited | Real estate | 2009 |
| THE Sussex Downs Ltd | Professional & scientific | 2026 |
| THE Tax Shop (Portsmouth) Limited | Administrative & support | 1994 |
| THE Towers SPV Limited | Real estate | 2021 |
| THE Townhouse 101 Ltd | Hospitality | 2024 |
| THE Trade Network Ltd | Information & communication | 2023 |
| THE Ultimate Building Company Ltd | Wholesale & retail | 2006 |
| THE University of Portsmouth Students' Union | Education | 2000 |
| THE Vapour Room (Portsmouth) Limited | Wholesale & retail | 2015 |
| THE Virtual Finance Director Limited | Professional & scientific | 2016 |
| THE West Group (Fluid Power) Limited | Manufacturing | 1982 |
| THE West London Tile Co Limited | Construction | 2008 |
| THE Winchester Arms Limited | Hospitality | 2025 |
| THE Window Centre (Devon) Ltd | Construction | 2023 |
| THE Window Centre (Newton Abbot) Ltd | Construction | 2026 |
| THE Winter Garden Company Ltd | Wholesale & retail | 2025 |
| THE Witterings Dental Practice Limited | Health & social care | 2007 |
| THE Woodfield Building Company Ltd | Construction | 2024 |
| THE Worstead Village Festival | Administrative & support | 2009 |
| THE Worx Portsmouth Ltd | Wholesale & retail | 2021 |
| THE Yachtsman Management Limited | Real estate | 2013 |
| Thebeautylounge Ltd | Health & social care | 2024 |
| Thejesterofcorals Ltd | Agriculture & fishing | 2025 |
| Themortgagepod Ltd | Financial services | 2021 |
| Theo Enterprises Limited | Construction | 2021 |
| Theorem Power Lift Recliners Limited | Other services | 2023 |
| Thepropertyportal Limited | Real estate | 2025 |
| Therapeutic Coaching Consultancy Ltd | Professional & scientific | 2023 |
| Thermaflow Heating & Plumbing Solutions Limited | Construction | 2021 |
| Thermal Insulation Engineering Ltd | Construction | 2017 |
| Thermawatt Ltd | Construction | 2017 |
| Thernfields Limited | Households | 2000 |
| These Hands Ltd | Health & social care | 2020 |
| These Woods Estates Ltd | Real estate | 2025 |
| Theskincollective Limited | Other services | 2026 |
| Theskinsanctuary Limited | Health & social care | 2025 |
| Thilakesh Cleaning Ltd | Administrative & support | 2018 |
| Think Partners Advisory Limited | Professional & scientific | 2025 |
| Thinking Makes IT SO Limited | Arts & recreation | 2025 |
| Thipthorpe Investments Limited | Administrative & support | 2024 |
| Third Venture Ltd | Wholesale & retail | 2022 |
| Thirdcenter Limited | Financial services | 2018 |
| Thirty Five KR Limited | Real estate | 2025 |
| Thirty One KR Limited | Real estate | 2025 |
| Thirty Something Collective Ltd | Construction | 2024 |
| Thirty Three KR Limited | Real estate | 2025 |
| This IS MEE Limited | Information & communication | 2025 |
| Thistle Management Consultants Limited | Professional & scientific | 2008 |
| Thistle Rose Property Ltd | Real estate | 2014 |
| Thomas Babb Brewing Company Limited | Administrative & support | 2016 |
| Thomas Bramwell Properties Limited | Real estate | 2023 |
| Thorin Enterprises Ltd | Information & communication | 2024 |
| Thornton Media Group Limited | Information & communication | 2018 |
| Three Fourteen Marketing Limited | Wholesale & retail | 2019 |
| Three Sixty Build Limited | Construction | 2018 |
| Three Sixty Property Group Limited | Real estate | 2025 |
| Thrive Technology Group Limited | Information & communication | 2016 |
| Throgmorton House Management Company Limited | Professional & scientific | 2010 |
| Thurlow Mansions Residents Limited | Households | 1999 |
| TIA Ikens PMO Services Ltd | Professional & scientific | 2025 |
| TIB Shelf Translations Community Interest Company | Professional & scientific | 2021 |
| TIC South Limited | Construction | 2024 |
| Tichada Limited | Health & social care | 2014 |
| Tide-Sy Limited | Administrative & support | 2017 |
| Tideaway Homes Ltd | Real estate | 2021 |
| Tidebank Holdings Limited | Financial services | 2016 |
| Tidebank Limited | Real estate | 2018 |
| Tidebank UK Limited | Real estate | 2009 |
| Tiger Safety Solutions Ltd | Administrative & support | 2024 |
| Tigersec Limited | Wholesale & retail | 2000 |
| Tight Lines Products Ltd | Wholesale & retail | 2024 |
| Tilia Tree Surgeons Ltd | Administrative & support | 2014 |
| Tilley Holdings Limited | Real estate | 2003 |
| Tilley Investments Limited | Financial services | 2021 |
| Tillisent Limited | Professional & scientific | 2000 |
| Tilly Fashion Limited | Wholesale & retail | 2026 |
| TIM AI Limited | Information & communication | 2026 |
| Timahs Luxury Ltd | Wholesale & retail | 2025 |
| Timber Fire & Stone Limited | Wholesale & retail | 2008 |
| Timberwise Construction Ltd | Construction | 2024 |
| Timeboxr Ltd | Information & communication | 2025 |
| Timefocus Limited | Real estate | 2001 |
| TIN TIN Chinese Ltd | Hospitality | 2025 |
| Tina Lawson Academy Ltd | Other services | 2019 |
| Tinayeli Ltd | Health & social care | 2016 |
| Tingewick Developments Limited | Construction | 2025 |
| Tintex & Wrapping Ltd | Wholesale & retail | 2015 |