| THE Property Guardians Solutions Ltd | Administrative & support | 2017 |
| THE Property Yard Ltd | Real estate | 2018 |
| THE Queens Road (Slough) Management Company Limited | Households | 1994 |
| THE Queer Club Ltd | Health & social care | 2018 |
| THE Reclamation FWO Ltd | Health & social care | 2025 |
| THE Refill Pantry Company Ltd | Wholesale & retail | 2025 |
| THE Reputation Atelier Ltd | Professional & scientific | 2026 |
| THE Resolution Consultancy Ltd | Health & social care | 2023 |
| THE Riddy Residents Association Limited | Households | 2008 |
| THE Ridings (Shillington) Management Company Limited | Households | 2013 |
| THE RM LAB Limited | Information & communication | 2020 |
| THE Rookery (Offley) Management Company Limited | Households | 2019 |
| THE Ruby Trading Company Limited | Wholesale & retail | 2004 |
| THE Saffron Property Services Company Ltd | Real estate | 2017 |
| THE Samuel Oscar Company Limited | Information & communication | 2005 |
| THE Scalp Room Limited | Other services | 2025 |
| THE School of Fishing Ltd | Education | 2010 |
| THE Sea Tree Limited | Hospitality | 2013 |
| THE Seat Lottery Society | Arts & recreation | 2018 |
| THE Shutter Repair & Maintenance Company Limited | Administrative & support | 2010 |
| THE Signing Company Limited | Education | 2015 |
| THE Signing Rooms Limited | Real estate | 2019 |
| THE Social Community Ltd | Education | 2025 |
| THE ST Paul's Walden Bury Estate Company Limited | Agriculture & fishing | 1933 |
| THE Statwood Partnership | | 1998 |
| THE Studio Letchworth Ltd | Other services | 2021 |
| THE Terrell Empire Ltd | Information & communication | 2018 |
| THE Thoughtful Group Limited | Financial services | 2008 |
| THE Toast Office Ltd | Hospitality | 2013 |
| THE Town Fryer (Hitchin) Limited | Hospitality | 2003 |
| THE Traction Owners Club Limited | Other services | 1994 |
| THE Trade Tribe Investments Ltd | Education | 2022 |
| THE Twin Pantry Ltd | Wholesale & retail | 2026 |
| THE Victoria Hitchin Limited | Hospitality | 2015 |
| THE Volunteer Tottenham Limited | Hospitality | 2023 |
| THE Watcher Straps & Co Ltd | Manufacturing | 2023 |
| THE WEE Vinoteca Ltd | Wholesale & retail | 2018 |
| THE Wellbeing POD (Hertfordshire) Limited | Other services | 2011 |
| THE White Wardrobe (Hitchin) Limited | Wholesale & retail | 2018 |
| THE Willian Trust Limited | Real estate | 1938 |
| THE Wine Tramp Limited | Wholesale & retail | 2020 |
| THE Workspace Agency Ltd | Real estate | 2025 |
| THE Write Girl Ltd | Arts & recreation | 2013 |
| THE Yoga Whole Limited | Education | 2024 |
| Theliwe Ltd | Health & social care | 2025 |
| Thesweenycollective Ltd | Administrative & support | 2025 |
| Theta Insulation Ltd | Construction | 2020 |
| Theydon Park Ltd | Real estate | 2019 |
| Think Outside the Box Marketing Limited | Professional & scientific | 2018 |
| Thinkalexander Ltd | Professional & scientific | 2026 |
| Thomas & Vines Ltd | Manufacturing | 1986 |
| Thomas Brooker & Sons Limited | Wholesale & retail | 1909 |
| Thomas Carter Limited | Construction | 2006 |
| Thomas Contracts Limited | Construction | 2017 |
| Thomas Hallam Consulting Limited | Professional & scientific | 2012 |
| Thomas Sorie Ibrahima Limited | Extraterritorial | 2025 |
| Thommo Electrical Services Ltd | Construction | 2026 |
| Thornton Gregory Limited | Administrative & support | 2016 |
| Thrive Caring Ltd | Health & social care | 2026 |
| Thrive Services Group Limited | Financial services | 2026 |
| Thunder Lane Ltd | Information & communication | 2026 |
| Thurlstone Limited | Information & communication | 1999 |
| TI22 Consultancy Ltd | Professional & scientific | 2025 |
| Tick in the Box Limited | Information & communication | 2004 |
| Tickbite Limited | Professional & scientific | 2026 |
| Tidy Taverns Limited | Hospitality | 2023 |
| Tier Aviation Ltd | Transport & logistics | 2025 |
| Tiffen Endless Summer Limited | Wholesale & retail | 2005 |
| Tiger Lily Accounting Limited | Professional & scientific | 2021 |
| Tilehouse Counselling | Health & social care | 2001 |
| TIM Price Consulting Ltd | Information & communication | 2025 |
| Tim-Mobile Limited | Wholesale & retail | 2014 |
| Timal Holdings Ltd | Financial services | 2023 |
| Time After Time (Antiques and Collectables) Limited | Wholesale & retail | 2018 |
| TIME2 Consulting Ltd | Professional & scientific | 2026 |
| Timely Support Services Limited | Administrative & support | 2020 |
| Timothy Knight Ventures Ltd | Wholesale & retail | 2025 |
| Tinys Taxis Ltd | Transport & logistics | 2017 |
| TIP and Tidy Limited | Water & waste | 2025 |
| Tippy Toes Ballet Limited | Arts & recreation | 2016 |
| Titan Carpentry Services Limited | Construction | 2026 |
| Titan Property Limited | Real estate | 2020 |
| Titus Investment Limited | Public administration | 2021 |
| Tj's E-Cigarettes Limited | Wholesale & retail | 2014 |
| Tj's E-Cigarettes Two Limited | Wholesale & retail | 2021 |
| TJS Exports Limited | Wholesale & retail | 2014 |
| TLM Tyres 24/7 Ltd | Wholesale & retail | 2025 |
| TM Burger Bites Limited | Hospitality | 2024 |
| TM Capital Partners Ltd | Real estate | 2025 |
| Toban Brand Consulting Limited | Professional & scientific | 2025 |
| Toco Homes Limited | Real estate | 2021 |
| Today Stays Ltd | Real estate | 2025 |
| Today-But-Then Limited | Administrative & support | 2018 |
| Toddington Industrial Coatings Limited | Construction | 2007 |
| Toftech Technology Limited | Information & communication | 2023 |
| Together Group Investments Ltd | Financial services | 2024 |
| Together Holding Group Ltd | Financial services | 2024 |
| Toginns Limited | Hospitality | 2026 |
| Toller Press Ltd | Information & communication | 2025 |
| TOM Donnelly Estates Ltd | Real estate | 2022 |