| Teralex Properties Limited | Real estate | 2016 |
| Teralon Media Limited | Information & communication | 2014 |
| Terra Quant Industries Limited | Information & communication | 2024 |
| Terrapon Services Ltd | Wholesale & retail | 2015 |
| Terriers Autos Ltd | Wholesale & retail | 2002 |
| Terriers Newsagents Limited | | 1989 |
| Testplus Limited | Information & communication | 2016 |
| Tetraspace Limited | Wholesale & retail | 2014 |
| Tetris Consulting Limited | Professional & scientific | 2017 |
| Tetsworth Taxis Limited | Transport & logistics | 2025 |
| TEULUM2020 Limited | Professional & scientific | 2020 |
| TEULUM21 Limited | Construction | 2021 |
| Tevo International Limited | Extraterritorial | 2004 |
| Tevo Limited | Extraterritorial | 2005 |
| Textile Automation Sales Limited | Manufacturing | 2001 |
| TF Fencing Limited | Construction | 2025 |
| Tfmm Ltd | Financial services | 2026 |
| Tfxl Ltd | Administrative & support | 2025 |
| TG Inventory and Property Services Ltd | Other services | 2015 |
| TGR Consultancy Limited | Other services | 2017 |
| Thai Exclusive Restaurant Ltd | Hospitality | 2025 |
| Thalir IT Limited | Information & communication | 2023 |
| Thames & Chiltern Honey Bees Ltd | Agriculture & fishing | 2022 |
| Thames & Country Investments Limited | Real estate | 2025 |
| Thames Air & Water Tech Limited | Water & waste | 2015 |
| Thames Electrical Services Ltd | Construction | 2016 |
| Thames Enterprises(Uk) Ltd | Other services | 2017 |
| Thames Lounge Ltd | Real estate | 2024 |
| Thames Nova Limited | Information & communication | 2020 |
| Thames Security Limited | Administrative & support | 2020 |
| Thames Valley Air Ambulance | Health & social care | 2000 |
| Thames Valley Air Ambulance (Leasing) Limited | Financial services | 2015 |
| Thames Valley Air Ambulance (Trading) Limited | Wholesale & retail | 2001 |
| Thames Valley Engineering & Training Limited | Real estate | 2002 |
| Thames Valley Motors Ltd | Wholesale & retail | 2020 |
| Thames Valley Mots Ltd | Wholesale & retail | 2025 |
| Thames Valley Pallets Ltd | Wholesale & retail | 2013 |
| Thames Valley Training & Development Ltd | Education | 2012 |
| Thames Valley Truck Parts Ltd | Wholesale & retail | 2026 |
| Thameside Aero Spares Limited | Wholesale & retail | 1963 |
| Thameside Holdings Limited | Financial services | 1981 |
| Thamesview (Plots 425 to 560) Residents Association Limited | Extraterritorial | 2003 |
| Thameswey Homes Limited | Professional & scientific | 1968 |
| Thamevalley Heating Ltd | Construction | 2022 |
| Thara Accountants Limited | Professional & scientific | 2016 |
| Thara Estate Group Ltd | Real estate | 2019 |
| Thara Homes Ltd | Real estate | 2020 |
| Thara Properties Ltd | Households | 2014 |
| Thara Properties Sales and Lettings Limited | Real estate | 2026 |
| Thara Stores Limited | Real estate | 2004 |
| Thara Supermarket Ltd | Wholesale & retail | 2023 |
| Thatcher Building & Construction Ltd | Construction | 2024 |
| Thatcher Tech Ltd | Information & communication | 2025 |
| THE Accreditor Limited | Extraterritorial | 2008 |
| THE Adrenaline Group Limited | Extraterritorial | 2020 |
| THE Alarm Surgery Limited | Professional & scientific | 2013 |
| THE Alternative Life Experiment Ltd | Information & communication | 2023 |
| THE Aluminium Cutting Company Limited | Administrative & support | 1992 |
| THE Animal Group Ltd | Professional & scientific | 2025 |
| THE APM Group Limited | Professional & scientific | 1993 |
| THE Arab International Construction Organisation | Extraterritorial | 2009 |
| THE Armory Depot Limited | Professional & scientific | 2024 |
| THE Audio BIT Ltd | Information & communication | 2019 |
| THE Avenue Number 4 Management Company Limited | Extraterritorial | 2005 |
| THE Avenue Number 5 Management Company Limited | Extraterritorial | 2005 |
| THE Bailey Sisters Ltd | Arts & recreation | 2007 |
| THE Barberland Trading Limited | Wholesale & retail | 2019 |
| THE Beacon Project Limited | Education | 2025 |
| THE Beaumont Park Management Company Limited | Extraterritorial | 1995 |
| THE Becs Global Ltd | Wholesale & retail | 2021 |
| THE Bell Inn at Ladbroke Limited | Hospitality | 2021 |
| THE Best Memories Limited | Arts & recreation | 2015 |
| THE Bezalel Funlab CIC | Education | 2025 |
| THE Big Friendly Grocer Limited | Wholesale & retail | 2024 |
| THE Bigger Giant Ltd | Professional & scientific | 2025 |
| THE Black Lion by Cask and Crew Limited | Hospitality | 2025 |
| THE Blue Banana Game Limited | Administrative & support | 2020 |
| THE Bouncy Bubble Company Ltd | Administrative & support | 2024 |
| THE Breme Park (Bromsgrove) Management Company Limited | Households | 2004 |
| THE Bricklayers by Cask and Crew Limited | Hospitality | 2025 |
| THE Burleigh Rise Management Company Limited | Extraterritorial | 1997 |
| THE Business of People Limited | Professional & scientific | 2004 |
| THE Butcher Management Limited | Other services | 2015 |
| THE Callard Company Ltd | Information & communication | 2021 |
| THE Canine Academy Buckinghamshire Ltd | Other services | 2017 |
| THE Canny Café Limited | Hospitality | 2018 |
| THE Caribbean Catering Company Ltd | Hospitality | 2018 |
| THE Carpet and Oven Wizard Ltd | Administrative & support | 2020 |
| THE Castle GIN School Limited | Other services | 2021 |
| THE Cattle Bar Co Ltd | Wholesale & retail | 2019 |
| THE Catwalk Emporium Ltd | Wholesale & retail | 2025 |
| THE Ceramic Tile Company Limited | Wholesale & retail | 1993 |
| THE Chalfonts Independent Grammar School Limited | Education | 2016 |
| THE Chapar Online Styling Limited | Wholesale & retail | 2016 |
| THE Chiltern Carpentry Company Limited | Construction | 2025 |
| THE Chilterns FOX Ltd | Information & communication | 2013 |
| THE Christmas Jumper Company Limited | Wholesale & retail | 2020 |
| THE Church of Jesus Christ of Latter-Day Saints (Great Britain) | Other services | 1961 |
| THE City of London Phonograph and Gramophone Society Limited | Arts & recreation | 1995 |
| THE Class Plan Ltd | Information & communication | 2024 |