| THE Boffin LAB Limited | Information & communication | 1997 |
| THE Canal Cottage Company Ltd | Arts & recreation | 2021 |
| THE Caring Beauty Co Ltd | Wholesale & retail | 2026 |
| THE Classic Decorating Company Limited | Construction | 1999 |
| THE Contented VET Ltd | Professional & scientific | 2021 |
| THE County Market Company Limited | Hospitality | 1999 |
| THE Courtyard Olney Diner Ltd | Hospitality | 2017 |
| THE Couture Studio Ltd | Manufacturing | 2024 |
| THE COW Roast Inn Ltd | Real estate | 2019 |
| THE Dembe Theatre Company Ltd | Administrative & support | 2026 |
| THE Designer Washstand Co Ltd | Wholesale & retail | 2018 |
| THE Dolly Show Ltd | Other services | 2023 |
| THE Dunsley Farm Shop Ltd | Wholesale & retail | 2024 |
| THE Elite Luxury Events Limited | Administrative & support | 2014 |
| THE Espresso Lounge Limited | Wholesale & retail | 2010 |
| THE Finance Provider Limited | Administrative & support | 1998 |
| THE Fluffy Dog Company Ltd | Other services | 2018 |
| THE Future IS Brighter Ltd | Real estate | 2021 |
| THE Glebe Cafe Limited | Hospitality | 2021 |
| THE Greener the Better Limited | Other services | 2007 |
| THE Guitar Engineer Limited | Manufacturing | 2022 |
| THE Hertfordshire Aesthetics Clinic Ltd | Health & social care | 2021 |
| THE Holm Edit Ltd | Professional & scientific | 2024 |
| THE Hospice Lottery Partnership Limited | Arts & recreation | 1997 |
| THE KEG & Cask Group Ltd | Professional & scientific | 2018 |
| THE Long Mile Limited | Other services | 2010 |
| THE Lorem Therapy Ltd | Health & social care | 2022 |
| THE Marmalade Cat Nurseries Ltd | Education | 2010 |
| THE Meadows Residents Company Limited | Households | 2003 |
| THE Mill Wilstone Management Company Limited | Households | 2003 |
| THE Mindful Birth Group Limited | Education | 2018 |
| THE Neopolymath Ltd | Information & communication | 2016 |
| THE Old Hospital (Cromer) Management Company Limited | Real estate | 2006 |
| THE Old Stables Ltd | Wholesale & retail | 2025 |
| THE on Services Group Limited | Information & communication | 2025 |
| THE People ARE Your Business Ltd | Administrative & support | 2022 |
| THE Pepper Foundation | Health & social care | 1993 |
| THE Rocket Scientist (Consultancy) Limited | Administrative & support | 2023 |
| THE Sandridge PUB Company (Unicorn) Ltd | Hospitality | 2019 |
| THE Sigidi Group Limited | Information & communication | 2021 |
| THE Speakable Method Limited | Information & communication | 2020 |
| THE Sustainable Health Foundation | Health & social care | 2019 |
| THE Taste Tree Limited | Administrative & support | 2018 |
| THE Travel Alchemist Limited | Administrative & support | 2020 |
| THE Tring Brewery Company Limited | Manufacturing | 1992 |
| THE Tring Partnership Limited | Professional & scientific | 2017 |
| THE Tringe Festival Ltd | Arts & recreation | 2013 |
| THE Tyre Changers Limited | Wholesale & retail | 2022 |
| THE Underground Group Limited | Other services | 2021 |
| THE White Lion (ST Leonards) Limited | Hospitality | 2017 |
| The-Game Ltd | Information & communication | 2024 |
| There IS NO Plan B Ltd | Construction | 2025 |
| Thetruffle Ltd | Wholesale & retail | 2019 |
| Things I Have Drawn Limited | Information & communication | 2017 |
| This IS Marketing Ltd | Professional & scientific | 2023 |
| Thompson Bradford Architects Ltd | Professional & scientific | 1996 |
| Thornbury (2000) Limited | Information & communication | 2001 |
| Thorpe Solutions Ltd | Construction | 2024 |
| Three Blackbirds Consulting Ltd | Information & communication | 2019 |
| Three Counties PAT Testing Limited | Professional & scientific | 2006 |
| Three Farms Limited | Extraterritorial | 2015 |
| Thursfield Properties Ltd | Households | 2014 |
| Ticaro Ltd | Professional & scientific | 2022 |
| TIE Holdings Limited | Financial services | 2019 |
| TIE Trustees Limited | Administrative & support | 2020 |
| Time and Place Ltd | Information & communication | 2026 |
| Tiverton Consulting Ltd | Professional & scientific | 2024 |
| TM Energy Limited | Professional & scientific | 2019 |
| TM Haulage Recruitment Ltd | Administrative & support | 2025 |
| TNT FX Ltd | Information & communication | 2026 |
| TOC Electrics Ltd | Construction | 2021 |
| Toch Technologies Limited | Information & communication | 2019 |
| TOM Barclay Holdings Ltd | Real estate | 2024 |
| Tomasino Emergency Care Services Ltd | Health & social care | 2021 |
| Toms Hill Estate Limited | Construction | 2004 |
| Tooview Consult Ltd | Information & communication | 2026 |
| Tornadoes Sports Education and Leisure | Education | 2020 |
| Total Balance Clinic Ltd | Health & social care | 2016 |
| Total Fitouts Corp UK Ltd | Construction | 2025 |
| Total Sports Ground Solutions Ltd | Arts & recreation | 2017 |
| TR IT Services Ltd | Information & communication | 2023 |
| Trade Supply Hub Ltd | Wholesale & retail | 2023 |
| Trademark Decorations Limited | Construction | 2020 |
| Trans-Euro Engineering Services Ltd | Wholesale & retail | 2004 |
| Transformation Through Leadership Limited | Education | 2010 |
| Transformative Health Solutions Ltd | Health & social care | 2020 |
| Travel Expressions Limited | Administrative & support | 2013 |
| Travel Impressions Limited | Administrative & support | 2011 |
| Travel View Network Ltd | Information & communication | 2018 |
| Travis Research Europe Limited | Administrative & support | 1996 |
| Tree Monkey Tree Care Ltd | Agriculture & fishing | 2015 |
| TRG Garden Maintenance Ltd | Administrative & support | 2024 |
| Tring Arts Trust Limited | Arts & recreation | 2009 |
| Tring Athletic Football Club Limited | Arts & recreation | 2026 |
| Tring Community Theatre Ltd | Education | 2026 |
| Tring Forum Limited | Real estate | 2005 |
| Tring Homes Limited | Construction | 1982 |
| Tring Motor Company Limited | Wholesale & retail | 2018 |
| Tring News Agents Ltd | Wholesale & retail | 2024 |
| Tring Park Cricket Limited | Wholesale & retail | 2019 |