| Thistledown Supported Living Limited | Health & social care | 2015 |
| Thlm Limited | Construction | 2019 |
| Thompson Solutions Limited | Public administration | 2019 |
| Thors Jets Ltd | Administrative & support | 2024 |
| Thoughtlights Ltd | Information & communication | 2013 |
| Thrale ST Cafe Ltd | Hospitality | 2016 |
| Thread HR Ltd | Administrative & support | 2022 |
| Three Sixteen Construction Limited | Construction | 2025 |
| Three YJE Properties Ltd | Real estate | 2024 |
| Thrive Always Limited | Wholesale & retail | 2025 |
| Thrive Living Limited | Real estate | 2024 |
| Thrpy Ltd | Health & social care | 2025 |
| Thru the Looking Glass AV Limited | Wholesale & retail | 2015 |
| THS Electrical Services Ltd | Construction | 2023 |
| Thurrock Podiatry Ltd | Health & social care | 2023 |
| Thyme and Tide Bar Ltd | Hospitality | 2026 |
| Tiana Art Ltd | Arts & recreation | 2026 |
| Tickle Pink Ltd | Arts & recreation | 2026 |
| Tilberry Ltd | Information & communication | 2024 |
| Tile Fixer Limited | Manufacturing | 2007 |
| Tillison Consulting Limited | Information & communication | 2008 |
| Tillys Interiors Ltd | Wholesale & retail | 2015 |
| Timber Nest Garden Rooms Limited | Construction | 2025 |
| Timber Windows (Southern) Limited | Construction | 2012 |
| Timber Windows of Hartley Wintney Limited | Construction | 2016 |
| Timber Windows of Sunningdale Limited | Construction | 2021 |
| Time & Place Luxury Holidays Limited | Administrative & support | 2006 |
| Time 4 Properties Ltd | Real estate | 2019 |
| Time for YOU Isle of Wight Limited | Administrative & support | 2015 |
| Time for YOU South Limited | Administrative & support | 2014 |
| Timsbury Consultancy Ltd | Information & communication | 2024 |
| TIN Racer Design Limited | Professional & scientific | 2000 |
| Tinstix Publishing Limited | Information & communication | 2024 |
| Tint Emsworth Limited | Other services | 2018 |
| Tiny Mood Ltd | Wholesale & retail | 2025 |
| Tiny Tumble Ltd | Administrative & support | 2022 |
| Titan Motorhomes and Caravans Ltd | Manufacturing | 2018 |
| Titanium Engineering Services Limited | Professional & scientific | 2018 |
| TJ Hearn Contracting Ltd | Construction | 2016 |
| TJA Autos Ltd | Wholesale & retail | 2023 |
| TJC Construction Limited | Construction | 2020 |
| TJC Defence Ltd | Construction | 2025 |
| TJC Equity Holdings Ltd | Real estate | 2025 |
| TJW Management Consultancy Limited | Professional & scientific | 2002 |
| TKM Homes Limited | Real estate | 2025 |
| TKR Fibre Ltd | Construction | 2021 |
| TL Distribution Ltd | Wholesale & retail | 2024 |
| TLB Automotive Ltd | Wholesale & retail | 2019 |
| TLB Driver Training Ltd | Education | 2026 |
| TLC Prestige Limited | Professional & scientific | 2021 |
| TLC Renovations Limited | Real estate | 2014 |
| TLC4PRINTERS Limited | Wholesale & retail | 2019 |
| TLF Plumbing and Heating Limited | Construction | 2016 |
| TLR Communications Ltd | Information & communication | 2019 |
| TMC Mortgage Associates Ltd | Financial services | 2023 |
| TME Property Services Limited | Real estate | 2025 |
| TMF Motors Limited | Wholesale & retail | 2013 |
| TMP Blast Parts Limited | Professional & scientific | 2019 |
| TMR Autohaus Limited | Wholesale & retail | 2025 |
| TMR Consulting Ltd | Extraterritorial | 2023 |
| Tnet Ltd | Information & communication | 2007 |
| TNF South Limited | Real estate | 2008 |
| TNI Installations Ltd | Construction | 2022 |
| TO Consultancy Services Limited | Professional & scientific | 2024 |
| Toats Mylk Limited | Wholesale & retail | 2019 |
| Toby Homes Limited | Construction | 2001 |
| TOC Domiciliary Care Ltd | Health & social care | 2025 |
| Today IS a Good Day for Science Ltd | Professional & scientific | 2025 |
| Tomes Architects Limited | Professional & scientific | 2022 |
| Tomis Maritime Services Ltd | Transport & logistics | 2024 |
| Tony Dawkins Associates Limited | Professional & scientific | 2015 |
| Tony Robb Flooring Services Ltd | Construction | 2005 |
| Tony Strugnell (Roofing) Ltd | Construction | 2025 |
| Tooes Investments Ltd | Real estate | 2024 |
| Tools for Tiles Limited | Extraterritorial | 2015 |
| Toothness Ltd | Health & social care | 2020 |
| Top Banana Flooring Ltd | Construction | 2023 |
| Top Day OUT Limited | Information & communication | 2016 |
| Top DEC Limited | Construction | 1999 |
| Top Dog Tattooz Limited | Arts & recreation | 2015 |
| Top G Barber 2 Ltd | Other services | 2026 |
| Top Marks Construction Limited | Construction | 2021 |
| Top Marks Decor Ltd | Construction | 2025 |
| Top Orchard Consulting Limited | Professional & scientific | 2013 |
| Top Tier Access and Maintenance Ltd. | Manufacturing | 2018 |
| Top-Notch Digital Edge Limited | Professional & scientific | 2024 |
| Topdots Orchestrations LLP | | 2015 |
| Topline Southern Holdings Limited | Professional & scientific | 2010 |
| Topline Window Fabrications Limited | Manufacturing | 2002 |
| Topmarks Healthcare Limited | Financial services | 2008 |
| Topnotch Building & Roofing Limited | Construction | 2021 |
| Topnotch Property Letting Limited | Real estate | 2022 |
| Topo 2436 Ltd | Wholesale & retail | 2025 |
| Topshelf Mixology Ltd | Hospitality | 2023 |
| Torch Education Ltd | Education | 2026 |
| Toro Watch Collection Ltd | Wholesale & retail | 2025 |
| Torque House Ltd | Wholesale & retail | 2026 |
| Torvik Limited | Real estate | 2021 |
| Total AI Group Ltd | Information & communication | 2024 |
| Total Communications Partnership Holdings Ltd | Professional & scientific | 2013 |