| Toptech Mart Limited | Wholesale & retail | 2024 |
| Toquis Ltd | Information & communication | 2020 |
| Torek Services Ltd | Health & social care | 2026 |
| Toria Brany Limited | Financial services | 2017 |
| Torii Martial Arts Association Limited | Arts & recreation | 2024 |
| Torin Lennons Devices Ltd | Wholesale & retail | 2025 |
| Tornello Ltd | Wholesale & retail | 2024 |
| Toro Protection Limited | Information & communication | 2019 |
| Torod Development Limited | Real estate | 2025 |
| Torre Property Services Limited | Construction | 2019 |
| Tortuga Vans Ltd | Wholesale & retail | 2021 |
| Torus Connect Limited | Information & communication | 2017 |
| Tosh Consultancy Limited | Professional & scientific | 2018 |
| Tosh Invests Ltd | Real estate | 2026 |
| Tosh Konsult Limited | Professional & scientific | 2022 |
| Tospino Ltd | Transport & logistics | 2026 |
| TOT Planning Limited | Manufacturing | 2015 |
| Total Clearance Services Ltd | Water & waste | 2025 |
| Total Dojo Limited | Arts & recreation | 2007 |
| Total Financial Services Limited | Financial services | 2007 |
| Total Grappling Limited | Arts & recreation | 2019 |
| Total Gymnastics Academies Limited | Arts & recreation | 2012 |
| Total Gymnastics Limited | Arts & recreation | 2008 |
| Total IT Experience Limited | Wholesale & retail | 2009 |
| Total Relocations Ltd | Transport & logistics | 2021 |
| Total Scents Ltd | Wholesale & retail | 2020 |
| Total Team Management Limited | Administrative & support | 2020 |
| Total Turf Solutions Limited | Professional & scientific | 2001 |
| Total-Play (Cricket Shield) Limited | Construction | 2026 |
| Total-Play Limited | Construction | 2007 |
| Totally Tiaras Ltd | Manufacturing | 2025 |
| Totally Toytastic Ltd | Wholesale & retail | 2017 |
| Tots & Dots Play Cafe Ltd | Hospitality | 2025 |
| Totus Associates Limited | Professional & scientific | 2008 |
| Touch of Timber Ltd | Wholesale & retail | 2022 |
| Touchpoint Resource Ltd | Administrative & support | 2010 |
| Touracars Limited | Wholesale & retail | 2025 |
| Tours Over Europe Limited | Other services | 1994 |
| Tove Trading Limited | Arts & recreation | 2022 |
| Tovey & Osborn Properties Ltd | Real estate | 2024 |
| Towcester Aesthetics Ltd | Other services | 2026 |
| Towcester Clinic Limited | Other services | 2026 |
| Tower Joinery Specialists Limited | Construction | 2002 |
| Tower Nursery Limited | Agriculture & fishing | 2013 |
| Towers Law Ltd | Professional & scientific | 2023 |
| Town & Country Maintenance Limited | Construction | 2013 |
| Toxicar Ltd | Transport & logistics | 2018 |
| Toy Junction & US Candy Club Ltd | Manufacturing | 2026 |
| Toy Toy Limited | Wholesale & retail | 2025 |
| Toya Formwork Ltd | Construction | 2024 |
| Toyotech Hybrid Autos Limited | Wholesale & retail | 2024 |
| Toyotech MOT Centre Ltd | Wholesale & retail | 2026 |
| Toys Insel Ltd | Wholesale & retail | 2024 |
| TP Electrical Contractor Ltd | Construction | 2023 |
| TP Rental Properties Ltd | Real estate | 2025 |
| TPA Support Limited | Extraterritorial | 2012 |
| Tpapa Global Venture Ltd | Construction | 2020 |
| Tpcontrols Ltd | Information & communication | 2018 |
| Tpjmk Limited | Hospitality | 2026 |
| TPV International Ltd | Information & communication | 2021 |
| TPX Financial Limited | Financial services | 2009 |
| TR Agents Ltd | Wholesale & retail | 2020 |
| TR Group Trading Limited | Professional & scientific | 2019 |
| TR Holdings Incorporated Ltd | Extraterritorial | 2017 |
| TR Izmir Limited | Hospitality | 2024 |
| TRA Motor Group Ltd | Wholesale & retail | 2025 |
| TRA Store Limited | Wholesale & retail | 2026 |
| Trabalho Investments Ltd | Real estate | 2018 |
| Trabalho Limited | Information & communication | 2016 |
| Trace PT Limited | Wholesale & retail | 2009 |
| Tracey and Jarvis TJ Ltd | Health & social care | 2020 |
| Tracing Services Limited | Administrative & support | 2009 |
| Track Limits Motorsport Ltd | Other services | 2024 |
| Track Zero Labs Ltd | Information & communication | 2023 |
| Track, Protection & Signalling Ltd | Construction | 2009 |
| Tracked Access Ltd | Administrative & support | 2021 |
| Trackrecord Construction Ltd | Construction | 2024 |
| Trackrecord Investments Ltd | Real estate | 2023 |
| Trackrecord Payroll Services Ltd | Other services | 2022 |
| Trackrecord Properties Limited | Real estate | 2020 |
| Trackrecords Management Services Limited | Professional & scientific | 2012 |
| Trackstone Limited | Wholesale & retail | 2022 |
| Tracr AI Ltd | Information & communication | 2025 |
| Tracr Construction Ltd | Construction | 2025 |
| Trade Away Limited | Wholesale & retail | 1994 |
| Trade Balustrade Ltd | Manufacturing | 2016 |
| Trade Car Remarketing Ltd | Wholesale & retail | 2016 |
| Trade City Brooklands Management Company Limited | Real estate | 2006 |
| Trade Door Limited | Other services | 1977 |
| Trade House Cars Ltd | Wholesale & retail | 2017 |
| Trade Training Specialists Ltd | Education | 2017 |
| Trade Vending Sales & Services Ltd | Manufacturing | 2017 |
| Tradeaxis Supply & Property Limited | Wholesale & retail | 2026 |
| Tradefixx Ltd | Professional & scientific | 2019 |
| Trademind Limited | Information & communication | 2014 |
| TRADENEST101 Ltd | Wholesale & retail | 2025 |
| Trader Lynk Limited | Information & communication | 2013 |
| Trades With AA Limited | Wholesale & retail | 2023 |
| Tradeteam Limited | Wholesale & retail | 1995 |
| Tradewise Insurance Services Limited | Financial services | 2002 |