| T & L Plant Limited | Construction | 1991 |
| T Shirt Export Ltd | Manufacturing | 2019 |
| T'Pau Ltd | Information & communication | 2025 |
| T.Hayden Art LLP | | 2021 |
| T.K.O Consulting Ltd | Information & communication | 2010 |
| Tablet Consulting LLP | | 2019 |
| Tact International Limited | Information & communication | 2017 |
| Tail-Or-Made Savile ROW Limited | Wholesale & retail | 2016 |
| Tailfin Advisory Ltd | Administrative & support | 2023 |
| Talent Fuse Partners Ltd | Administrative & support | 2022 |
| Talentscape Solutions Limited | Construction | 2023 |
| Tales Enterprise Ltd | Information & communication | 2024 |
| Tang Investment NO1 Limited | Financial services | 2023 |
| Tanning Lounge and Beauty Limited | Other services | 2011 |
| TAP Tour Management Service Ltd | Professional & scientific | 2012 |
| Taplow Quay Management Company Limited | Households | 2004 |
| Taps "N" Tiles Limited | Construction | 2024 |
| Tara Rule Ltd | Administrative & support | 2021 |
| Target Equity Ltd | Professional & scientific | 2023 |
| Tarramy Limited | Professional & scientific | 2007 |
| Tasch Limited | Information & communication | 2018 |
| Tatu Limited | Arts & recreation | 2012 |
| Tatu Store Limited | Wholesale & retail | 2022 |
| Taylor Made Productions Ltd | Information & communication | 2020 |
| TBL Solutions Ltd | Construction | 2026 |
| Tbmd Consultancy Ltd | Wholesale & retail | 2024 |
| Tdcm UK Ltd | Professional & scientific | 2011 |
| Team Ashcroft Limited | Professional & scientific | 2022 |
| Teatimers Childcare Limited | Education | 2016 |
| Techdreams Solutions Limited | Information & communication | 2022 |
| Techreate Ltd | Information & communication | 2019 |
| Techtronic Industries (UK) Ltd | Wholesale & retail | 1990 |
| Tedwood Holdings Limited | Households | 2022 |
| Tekfen Engineering UK Limited | Professional & scientific | 2022 |
| Telehealth Central Ltd | Professional & scientific | 2019 |
| Television Systems Holdings Limited | Financial services | 2011 |
| Telexsus Limited | Wholesale & retail | 2010 |
| Tempest Smith & Company Limited | Other services | 2003 |
| Templar Brooks Ltd | Real estate | 2017 |
| Templars Place (Marlow) Residents Management Company Limited | Households | 1980 |
| Temple Island Management Limited | Households | 1980 |
| Tenmproducts Ltd | Wholesale & retail | 2018 |
| Tennis Exclusive Coaching and Management Ltd | Administrative & support | 2011 |
| Test Concepts Ltd | Professional & scientific | 2018 |
| Test-Tech Print Ltd | Professional & scientific | 2017 |
| TGL Enterprises Limited | Hospitality | 2025 |
| Tgtg Limited | Arts & recreation | 2007 |
| Thames & Country Limited | Real estate | 2020 |
| Thames Bridge Accountants Limited | Professional & scientific | 2012 |
| Thames Bridge Properties Limited | Real estate | 2010 |
| Thames Club Holdings Ltd | Financial services | 2024 |
| Thames Path Consulting Ltd | Professional & scientific | 2023 |
| Thames Talent Partners Limited | Administrative & support | 2025 |
| Thames Valley Construction Training Association Limited | Construction | 1991 |
| Thamesfield Consulting Limited | Information & communication | 2018 |
| THE Angel of History Limited | Arts & recreation | 2026 |
| THE Barn Club Limited | Other services | 2014 |
| THE Beacon PR Ltd | Professional & scientific | 2023 |
| THE Black Book Group Ltd. | Administrative & support | 2014 |
| THE Butcher’S TAP & Grill Limited | Hospitality | 2017 |
| THE CFO Consultancy Ltd | Professional & scientific | 2020 |
| THE Chalk Free House Ltd | Hospitality | 2023 |
| THE Chalk Stone Brewery Limited | Extraterritorial | 2016 |
| THE Cheesy Grape Company Limited | Hospitality | 2024 |
| THE Childrens Shoe Company Limited | Wholesale & retail | 2012 |
| THE Coaching Method Ltd | Other services | 2022 |
| THE Collaboration Club Ltd | Administrative & support | 2023 |
| THE Consumer Polling Company Ltd | Professional & scientific | 2024 |
| THE Core Resource Limited | Professional & scientific | 2001 |
| THE Denville Players Limited | Arts & recreation | 2025 |
| THE Design Cabin Community C.I.C. | Professional & scientific | 2020 |
| THE Design Cabin Ltd | Professional & scientific | 2020 |
| THE Desired House Ltd | Construction | 2018 |
| THE Ducks Event Rentals Ltd | Hospitality | 2025 |
| THE Electric Boat Company Ltd | Manufacturing | 2015 |
| THE Facade Organisation Limited | Extraterritorial | 2019 |
| THE Flower Studio Limited | Wholesale & retail | 2009 |
| THE Forty-Two Queens Road Twickenham Management Company Limited | Households | 1994 |
| THE Francis FIC | Financial services | 2019 |
| THE FST Group Ltd | Professional & scientific | 2007 |
| THE Garden Mews Residents Company Limited | Households | 2005 |
| THE Good EGG Corporate Consulting & Coaching Ltd | Administrative & support | 2025 |
| THE Halloumi Cheese Co. Ltd | Manufacturing | 2020 |
| THE Happiness Puzzle Ltd | Education | 2024 |
| THE Harleyford Estate Group of Companies Limited | Professional & scientific | 2010 |
| THE Healthy Minds Hub Ltd | Health & social care | 2023 |
| THE Heights Management Company (High Wycombe) Limited | Households | 2000 |
| THE Heights Management Company (Marlow) Limited | Households | 1993 |
| THE Home Renovation Experts Limited | Construction | 2019 |
| THE House of Cars Limited | Wholesale & retail | 1996 |
| THE House of Jacu Ltd | Wholesale & retail | 2020 |
| THE Identity Organisation Ltd | Information & communication | 2010 |
| THE JAM Academy Ltd | Education | 2013 |
| THE Kiln Shed Ltd | Extraterritorial | 2020 |
| THE Kindness Exchange Ltd | Professional & scientific | 2022 |
| THE Label System Company Ltd | Other services | 2019 |
| THE Lemonade Stand Group Ltd | Professional & scientific | 2026 |
| THE Link Foundation | Health & social care | 2007 |
| THE Listening Planet Ltd | Administrative & support | 2023 |
| THE Lowood Alliance | | 2008 |