| Trumpington Meadows Delivery & Action Group Ltd | Other services | 2020 |
| Trumpington Property Management Ltd | Real estate | 2025 |
| Trumpington Residents' Association | Other services | 2008 |
| Trumpington Vista Management Company Limited | Households | 2017 |
| Trust Homecare Solution Limited | Administrative & support | 2017 |
| Trusted Advisor Ltd | Financial services | 2001 |
| Trusted Secretarial Services Limited | Administrative & support | 2012 |
| Trustfold Ltd | Information & communication | 2025 |
| Trustonic Limited | Information & communication | 2011 |
| Trutina Therapeutics Ltd | Professional & scientific | 2023 |
| Truvisai Ltd | Information & communication | 2025 |
| TRX Biosciences Limited | Professional & scientific | 2019 |
| TRY Best Ltd | Manufacturing | 2024 |
| TS & AM Limited | Hospitality | 2025 |
| TS Golf Ltd | Wholesale & retail | 2022 |
| Ts&T Limited | Administrative & support | 2018 |
| TSE Electrical Services Limited | Construction | 2014 |
| TSG Avioservices Ltd | Manufacturing | 2025 |
| TSH Consulting Ltd | Professional & scientific | 2011 |
| Tsingshan Group Limited | Manufacturing | 2026 |
| Tsky Stationery Co., Limited | Wholesale & retail | 2017 |
| TSL Group Holdings Ltd | Financial services | 2025 |
| TSM Build Ltd | Construction | 2018 |
| TSN Consultants Ltd | Construction | 2018 |
| Tsong Biotechnology (UK) Limited | Wholesale & retail | 2019 |
| TSR Alliance Ltd | Real estate | 2025 |
| Tsso Nuclear Limited | Wholesale & retail | 2024 |
| Tswtrading Limited | Professional & scientific | 2013 |
| TT Secure Platform Limited | Information & communication | 2024 |
| Tt&W Limited | Professional & scientific | 2008 |
| TTD Tickets Ltd | Wholesale & retail | 2024 |
| TTI Consultants Ltd | Professional & scientific | 2024 |
| TTI Property Services Ltd | Real estate | 2026 |
| TU Analysis Ltd | Information & communication | 2024 |
| TU Casa Restaurant Ltd | Hospitality | 2016 |
| Tubeworx Limited | Manufacturing | 2014 |
| Tubing International Limited | Administrative & support | 2021 |
| Tudmill Ltd. | Professional & scientific | 2010 |
| Tudor Accounts Ltd | Professional & scientific | 2016 |
| Tudor Meadows Residents Limited | Real estate | 2010 |
| Tudorbox Limited | Manufacturing | 2025 |
| Tudotec Consulting Limited | Professional & scientific | 2024 |
| Tulip Business Solutions Ltd | Professional & scientific | 2016 |
| Tullamore Investments Limited | Professional & scientific | 2015 |
| Tumaris International Ltd | Hospitality | 2022 |
| Tumchi Limited | Health & social care | 2019 |
| Tumo Limited | Professional & scientific | 2023 |
| Tumourvue Ltd | Manufacturing | 2018 |
| Tuntara Pathways Ltd | Professional & scientific | 2025 |
| Turbo Blade Limited | Manufacturing | 2024 |
| Turcu.Nicu Ltd | Manufacturing | 2026 |
| Turkish Accountant Ltd | Professional & scientific | 2020 |
| Turn Key Apartments Limited | Extraterritorial | 2020 |
| Turn Pages UK Limited | Wholesale & retail | 2025 |
| Turner Mechanical Services Ltd | Construction | 2018 |
| Turners (Wyevale) Management Company Limited | Households | 2006 |
| Turners Management Company Limited | Households | 2005 |
| Turney & Associates Lettings LLP | | 2009 |
| Turney Holdings Limited | Administrative & support | 2024 |
| Turney Management Ltd | Real estate | 2010 |
| Turneys Court Property Co Ltd | Households | 2007 |
| Turning the Red Lights Green | Health & social care | 2005 |
| Turnstone (Cambridge) Limited | Construction | 1995 |
| Turnstone Bedford Limited | Construction | 2016 |
| Turnstone Cambridge Developments Ltd | Construction | 1996 |
| Turnstone Colchester Ltd | Construction | 1999 |
| Turnstone Estates Limited | Real estate | 1989 |
| Turnstone Real Estate Limited | Construction | 2012 |
| Turnstone Southend Limited | Construction | 2012 |
| Turnstone Special Projects Limited | Construction | 2012 |
| Turnstone ST Neots Limited | Construction | 2012 |
| Turnstone Waterbeach Limited | Construction | 1999 |
| Turnwood Heritage Limited | Extraterritorial | 2016 |
| Turnwood Limited | Real estate | 2019 |
| Turtle Dove Cambridge Community Interest Company | Health & social care | 2013 |
| Tusaac Ltd | Manufacturing | 2024 |
| Tusaqua Limited | Real estate | 2017 |
| Tuscanio Ltd | Wholesale & retail | 2025 |
| Tuscany House (Management) Limited | Real estate | 1983 |
| Tusingnis Limited | Real estate | 2017 |
| Tuslignum Limited | Real estate | 2017 |
| Tuspark (Newcastle) Limited | Real estate | 2017 |
| Tuspark Holdings (UK) Limited | Real estate | 2017 |
| Tuspark Investment & Management Limited | Financial services | 2017 |
| Tusterra Limited | Real estate | 2017 |
| Tusting & Twyman Limited | Professional & scientific | 2011 |
| Tutelar Security Technology Co., Ltd | Manufacturing | 2024 |
| Tutello Limited | Information & communication | 2023 |
| Tutu Limited | Real estate | 1998 |
| TV Business Ltd | Professional & scientific | 2023 |
| TW Health AID Ltd | Health & social care | 2021 |
| Tweedledum Limited | Information & communication | 2025 |
| Twelve Valeting Limited | Wholesale & retail | 2021 |
| Twelve Winds Limited | Professional & scientific | 2008 |
| Twenty Four Frames PER Second Films Ltd. | Information & communication | 2008 |
| Twenty Seven 77 Ltd | Professional & scientific | 2018 |
| TWENTY5 Planning Limited | Professional & scientific | 2025 |
| Twentyforty | Professional & scientific | 2026 |
| Twentytwo Capital Partners Limited | Financial services | 2025 |
| TWI Certification Limited | Other services | 1995 |