| TSP Projects Limited | Construction | 1995 |
| TSR Scuba Limited | Wholesale & retail | 2024 |
| TT Accounting Services Ltd | Professional & scientific | 2026 |
| TT Burgers Ltd | Hospitality | 2024 |
| TT Electrical Ltd | Construction | 2018 |
| TTS Training Ltd | Education | 2018 |
| Tudor Jenkins & Company Limited | Professional & scientific | 1972 |
| Tuesday Property Limited | Real estate | 2014 |
| Tuesday PUB Club Ltd | Hospitality | 2026 |
| Tukans Limited | Wholesale & retail | 2001 |
| Tulip Elite Limited | Professional & scientific | 2022 |
| Tulip Residential Estates Ltd | Real estate | 2023 |
| Tullivers Limited | Wholesale & retail | 2016 |
| Tulloch Residential Limited | Construction | 2024 |
| Tundra Point (Emersons Green) Management Company Limited | Households | 2017 |
| Tuneless Choir Ltd | Arts & recreation | 2016 |
| Turbo Transport Limited | Transport & logistics | 2025 |
| Turfgrass Services International Limited | Agriculture & fishing | 1989 |
| Turn Key Projects Limited | Wholesale & retail | 1992 |
| Turnaround (Yorkshire) Ltd | Manufacturing | 2019 |
| Turnbulls (York) Holdings Limited | Real estate | 2015 |
| Turner Little (Deutschland) Limited | Professional & scientific | 2004 |
| Turner Little Company Nominees Limited | Professional & scientific | 2000 |
| Turner Little Company Secretaries Limited | Professional & scientific | 2000 |
| Turner Little Consulting Limited | Professional & scientific | 2000 |
| Turner Little Limited | Financial services | 1998 |
| Turnerround (Services) Limited | Administrative & support | 2013 |
| Turnwalk Limited | Construction | 1986 |
| Turtle Bay Swim Academy Ltd | Education | 2026 |
| Turtle Key Productions Limited | Arts & recreation | 2021 |
| Tutor LED Learning Ltd | Education | 2020 |
| Tutor Vision Ltd | Education | 2024 |
| Tutorfox Ltd | Education | 2023 |
| Tutoring for ALL Limited | Education | 2020 |
| TW Fields (Osbaldwick Land) Limited | Real estate | 2014 |
| Twelve Oaks Software Ltd | Information & communication | 2014 |
| Twenty First Century Developments Ltd | Real estate | 2021 |
| Twenty First Century-Fox Limited | Professional & scientific | 1991 |
| Twenty Five (York) Ltd | Construction | 2017 |
| TWG Group Limited | Professional & scientific | 2015 |
| TWH Homes Ltd | Real estate | 2015 |
| TWH2 Ltd | Real estate | 2019 |
| Twiddlebit Software Ltd | Information & communication | 2004 |
| Twiglet and ROO Ltd | Administrative & support | 2026 |
| Twiin Holdings Limited | Real estate | 2019 |
| Twin Bloom Consulting Limited | Professional & scientific | 2026 |
| Twine and Barrel Limited | Hospitality | 2018 |
| Twisted IP Limited | Professional & scientific | 2015 |
| Twisted Pair Solutions Limited | Professional & scientific | 2013 |
| Two Cat Consulting Limited | Information & communication | 2022 |
| Two Cherries (York) Limited | Hospitality | 2019 |
| Two Four Music Publishers Limited | Information & communication | 1967 |
| Two Four Twenty Four Ltd | Information & communication | 2021 |
| Two Goose Limited | Hospitality | 2024 |
| Two Heads Consultants Ltd | Professional & scientific | 2024 |
| Two Jays Catering Limited | Hospitality | 2014 |
| Two Lees Ltd | Construction | 2021 |
| Two of York Limited | Real estate | 2015 |
| Two OR More Bakes Ltd | Wholesale & retail | 2026 |
| Two Point Zero Marketing Limited | Professional & scientific | 2013 |
| Two Roots Floristry Ltd | Wholesale & retail | 2026 |
| Two Siblings Food Limited | Manufacturing | 2026 |
| Two Trails Ltd | Hospitality | 2022 |
| Twobramblings (Holdings) Limited | Health & social care | 2021 |
| Twobramblings Limited | Health & social care | 2021 |
| Twobytwo Ltd | Administrative & support | 2025 |
| TY Braou Solutions Ltd | Professional & scientific | 2025 |
| Tylexia Ltd | Hospitality | 2024 |
| Tyneside Minimix (Concrete) Limited | Construction | 1991 |
| Tyre Traders Direct Ltd | Wholesale & retail | 2017 |
| Tyresavings Limited | Wholesale & retail | 2017 |
| Tyresoft Limited | Information & communication | 2011 |
| Tyson Moore Holdings Limited | Financial services | 2020 |
| Tyson Moore Limited | Administrative & support | 2014 |
| Tyszyk & Ballester Developments Ltd | Real estate | 2023 |
| U.K. Yorkwell Intelligence Technology Ltd | Information & communication | 2018 |
| UHY Calvert Smith Audit Ltd | Professional & scientific | 2022 |
| UHY Calvert Smith LLP | | 2016 |
| UHY Calvert Smith Probate Ltd | Professional & scientific | 2015 |
| UK Agri-Tech Centre Limited | Agriculture & fishing | 2023 |
| UK Autoelectrics Ltd | Wholesale & retail | 2019 |
| UK Bagging Ltd | Transport & logistics | 2020 |
| UK Business Registry Limited | Professional & scientific | 2015 |
| UK Case Management Limited | Health & social care | 2008 |
| UK Clinical Neuropsychology Ltd. | Professional & scientific | 2019 |
| UK Consumables Limited | Wholesale & retail | 2020 |
| UK Digital Sales Limited | Wholesale & retail | 2024 |
| UK Eastsail Ltd | Wholesale & retail | 2020 |
| UK Emergency Vehicles Ltd | Extraterritorial | 2013 |
| UK Farm Vets Limited | Extraterritorial | 2010 |
| UK Farm Vets North Limited | Extraterritorial | 2014 |
| UK Franchise Consultants Ltd | Administrative & support | 2022 |
| UK Global Road Safety Ltd | Public administration | 2012 |
| UK Holiday Park Awards Ltd | Arts & recreation | 2024 |
| UK IO Leisure Ltd | Hospitality | 2018 |
| UK Juicers Limited | Wholesale & retail | 2002 |
| UK Medical Freedom Alliance Ltd | Professional & scientific | 2020 |
| UK Pilates People Ltd | Arts & recreation | 2021 |
| UK PUB Management Group Ltd | Hospitality | 2025 |
| UK Radio Systems Limited | Information & communication | 2016 |