| TML Construction Limited | Professional & scientific | 2012 |
| TML Contractors (UK) Limited | Construction | 2014 |
| TML Truck and Commercials Export Ltd | Wholesale & retail | 2025 |
| TMS Contract Services Ltd | Professional & scientific | 2025 |
| TN Engineering Services Ltd | Real estate | 2023 |
| Today Forever (Cambridge) Limited | Other services | 2026 |
| Today Forever (Leeds) Limited | Other services | 2026 |
| Today Forever Limited | Other services | 2025 |
| Toennies Fleisch UK Ltd | Professional & scientific | 2006 |
| Toft Estates Limited | Construction | 2023 |
| Toft Farming Limited | Agriculture & fishing | 2019 |
| Toft Sports Ltd | Wholesale & retail | 2025 |
| Tokos Trans Ltd | Transport & logistics | 2015 |
| Toledo House Ltd | Hospitality | 2021 |
| TOM Trotter Ltd | Information & communication | 2021 |
| Tomas Svirplys Ltd | Transport & logistics | 2017 |
| Tomas&Vika Ltd | Transport & logistics | 2019 |
| Tomasso 74 Ltd | Transport & logistics | 2017 |
| Tomasz Wolanin Limited | Administrative & support | 2014 |
| Tombur Limited | Wholesale & retail | 2025 |
| Tomkemp Ltd | Wholesale & retail | 2019 |
| Tomo Campbell Ltd | Other services | 2022 |
| Tomson & Wotton Limited | Manufacturing | 2005 |
| Toneville Limited | Transport & logistics | 2010 |
| Tonwood DIY Ltd | Wholesale & retail | 2014 |
| Tonwood Holdings Limited | Financial services | 2023 |
| Tony Building Ltd | Construction | 2023 |
| Tony Nicolaou Driver Training Ltd | Education | 2025 |
| Tony's Roofing and Guttering Services Ltd | Construction | 2024 |
| Tonyxt Ltd | Other services | 2017 |
| Top Cleaning and Domestic Services Limited | Administrative & support | 2025 |
| Top CUE Consultancy (UK) Ltd | Professional & scientific | 2020 |
| Top Haulage Ltd | Transport & logistics | 2026 |
| Top Quality Roofing Ltd | Construction | 2014 |
| Top Solutions Limited | Administrative & support | 2018 |
| Top Tier Property Maintenance Ltd | Construction | 2026 |
| Top UP Resources Limited | Administrative & support | 2014 |
| Topping Spalding Ltd | Hospitality | 2024 |
| Toppings Spalding Ltd | Hospitality | 2026 |
| Torien Services Limited | Construction | 2008 |
| Total Branded Solutions Ltd | Manufacturing | 2014 |
| Total Home Roofing and Building (DL) Ltd | Construction | 2022 |
| Total Home Roofing and Building (Eastern) Ltd | Construction | 2025 |
| Total Landscapes & General Builders Ltd | Construction | 2018 |
| Total Landscapes (Cambs) Ltd | Construction | 2018 |
| Total Landscapes (Lincs) Ltd | Administrative & support | 2018 |
| Total Landscapes Fenland Ltd | Construction | 2018 |
| Total Paving & Resin Ltd | Administrative & support | 2026 |
| Total Property Solutions (East) Ltd | Construction | 2024 |
| Totally Ordinary Limited | Real estate | 2012 |
| Totalprint Limited | Manufacturing | 1981 |
| Towlers Coaches Ltd | Transport & logistics | 2003 |
| Town and City Property and Garden Maintenance Ltd | Construction | 2014 |
| Town and County Roofing Ltd | Construction | 2024 |
| TP Motorsport Ltd | Arts & recreation | 2023 |
| TPM (Lincs) Limited | Construction | 2018 |
| TPM Group Limited | Construction | 2017 |
| TPM Lincs (Spalding) Ltd | Construction | 2020 |
| Tra-Vu Tech Limited | Information & communication | 2025 |
| Tracey Dawn 2016 Ltd | Administrative & support | 2016 |
| Tradesman Near YOU Ltd | Information & communication | 2020 |
| Tradewise Paving Solutions Ltd | Administrative & support | 2026 |
| Trading 500 Ltd | Wholesale & retail | 2023 |
| Traffic Engineering Services Ltd. | Manufacturing | 1998 |
| Traffic Solutions Limited | Transport & logistics | 2026 |
| Tramline TEC Ltd | Wholesale & retail | 2021 |
| Trans KAR Ltd | Transport & logistics | 2015 |
| Trans Ltd | Transport & logistics | 2015 |
| Trans Marian Limited | Transport & logistics | 2013 |
| Transaul Limited | Transport & logistics | 2018 |
| Transayan Ltd | Administrative & support | 2016 |
| Transgan Ltd | Transport & logistics | 2021 |
| Transhire Limited | Hospitality | 1996 |
| Transilvania Land Limited | Transport & logistics | 2017 |
| Transkop Ltd | Transport & logistics | 2021 |
| Transport Compliance & Management Limited | Professional & scientific | 2015 |
| Transport DCP Limited | Transport & logistics | 2015 |
| Travelura Ltd | Administrative & support | 2025 |
| Traxxis Ltd | Wholesale & retail | 2019 |
| Treewise (Lincs) Ltd | Agriculture & fishing | 2013 |
| Treidi Ltd | Manufacturing | 2024 |
| Trevor Chinery Limited | Other services | 2012 |
| Tri-All Services Ltd | Construction | 2022 |
| Triactive Limited | Wholesale & retail | 2010 |
| Tribe Together CIC | Construction | 2023 |
| TRINITY1 Capital Limited | Financial services | 2019 |
| TRINITY1 Construction Limited | Financial services | 2026 |
| TRINITY1 Investments Limited | Real estate | 2018 |
| Triple C (Boston) Limited | Arts & recreation | 2018 |
| Triple D Trading Limited | Wholesale & retail | 2022 |
| Triplek Engineering Ltd | Professional & scientific | 2022 |
| Tripp Brickwork & Building Services Ltd | Construction | 2017 |
| Triton Roofing UK (South) Ltd | Construction | 2023 |
| Triunfador Healthcare Limited | Health & social care | 2025 |
| Trixs 2010 Ltd | Transport & logistics | 2022 |
| Troonfield Ltd | Professional & scientific | 2024 |
| Tropical Island Rentals Limited | Administrative & support | 2023 |
| TRS Roof Solutions Ltd | Construction | 2020 |
| TRT Services Ltd | Transport & logistics | 2020 |
| True Blue Marine Ltd | Manufacturing | 2023 |