| Top Tuning Limited | Wholesale & retail | 2017 |
| Topcut Gents Barbers Ltd | Other services | 2025 |
| Tora KAI Karate South West Ltd | Education | 2025 |
| Tornado of Sales Ltd | Wholesale & retail | 2025 |
| Total Carpentry (Wiltshire) Limited | Construction | 2016 |
| Total Fire and Security Limited | Administrative & support | 2006 |
| Total House Clearance Ltd | Water & waste | 2025 |
| Total Pro Soccer Limited | Education | 2012 |
| Total Training Consultancy Limited | Education | 2003 |
| Total Tyre Management Ltd | Wholesale & retail | 2015 |
| Touba Offshore Maintenance Ltd | Manufacturing | 2023 |
| Touch Electrical Limited | Construction | 2007 |
| Towan Lodges Management Company Limited | Households | 2021 |
| Town & Country Developers Limited | Real estate | 2000 |
| Townsend Design and Print Ltd | Manufacturing | 2019 |
| Toys Ahoy Limited | Wholesale & retail | 2012 |
| TP Heating Services Ltd | Construction | 2020 |
| Tpcs Powder Coating (UK) Limited | Wholesale & retail | 2014 |
| Tpvc Chippenham Ltd | Professional & scientific | 2024 |
| Tq's Barbershop Ltd | Other services | 2021 |
| Tracey Moloney Academy Ltd | Education | 2026 |
| Tracey Moloney Holdings Ltd | Financial services | 2025 |
| Training & Coating Consultants Limited | Professional & scientific | 2015 |
| Tranrate Limited | Information & communication | 1988 |
| Trans European Holdings Limited | Extraterritorial | 1969 |
| Transapt Ltd | Arts & recreation | 2015 |
| Transcendent Law Ltd | Professional & scientific | 2022 |
| Transform Energy Consulting Ltd | Professional & scientific | 2016 |
| Transocean Anti-Corrosion Limited | Professional & scientific | 2003 |
| Traynor Property Holdings Limited | Real estate | 2019 |
| TRE Portsmouth Ltd | Arts & recreation | 2020 |
| Tree Resource Limited | Agriculture & fishing | 2019 |
| Trees ETC Limited | Professional & scientific | 2024 |
| Tremadoc Limited | Professional & scientific | 2023 |
| Trescaminos Ltd | Real estate | 2020 |
| Trevow Holdings Ltd | Financial services | 2024 |
| TRH Industries Limited | Information & communication | 2019 |
| Tribrach Ltd | Construction | 2012 |
| Trickledown Stud Limited | Agriculture & fishing | 2004 |
| Trilateral Solutions Ltd | Administrative & support | 2004 |
| Trinity Lettings and Maintenance Limited | Construction | 2022 |
| Trinity Manna Ltd | Real estate | 2023 |
| Triptych Furniture Ltd | Manufacturing | 2015 |
| TRS Communications Limited | Financial services | 2013 |
| Truck Van Car Limited | Extraterritorial | 2014 |
| Truckmaster UK Limited | Transport & logistics | 2016 |
| True Gent Tattoos Ltd | Other services | 2022 |
| True North International Limited | Professional & scientific | 2023 |
| Truecore Consulting Limited | Information & communication | 2024 |
| Trust Solar Wholesale Ltd | Construction | 2022 |
| Trusted Appliance Repairs Ltd | Manufacturing | 2026 |
| Truston Limited | Administrative & support | 2008 |
| Truston Security Systems Limited | Administrative & support | 2026 |
| Tsalach Global Solutions Limited | Information & communication | 2024 |
| TSD Hire Ltd | Administrative & support | 2023 |
| TTG Technology (Europe) Limited | Administrative & support | 2010 |
| TTL Ground Services and Landscaping Ltd | Construction | 2026 |
| Tubb Property Services Ltd | Professional & scientific | 2024 |
| Tuckie’S Bargain Depot Ltd | Wholesale & retail | 2026 |
| Tudor's Kitchens Limited | Construction | 2018 |
| Tufplate Engineering Limited | Extraterritorial | 1998 |
| Tulip Laundry Ltd | Other services | 2025 |
| TUM Somnum Ltd | Health & social care | 2019 |
| Turkish Style Barber MP Ltd | Other services | 2025 |
| Turner Osteopathy Ltd | Health & social care | 2019 |
| Turners Brickworks Limited | Construction | 2026 |
| Turtledove Health Limited | Administrative & support | 2014 |
| Tutorweb Ltd | Education | 2020 |
| Tveez Ltd | Information & communication | 2024 |
| Tvmpp Holdings Limited | Administrative & support | 2026 |
| TW Construction (Chippenham) Ltd | Construction | 2025 |
| TW Wills Ltd | Other services | 2025 |
| Twin Suns Living Ltd | Real estate | 2025 |
| Two Bellies Creative Ltd | Professional & scientific | 2026 |
| Two Kimmish Ltd | Professional & scientific | 2026 |
| TWO70 Digital Limited | Information & communication | 2016 |
| Tyley Valley Sporting Club | Arts & recreation | 2022 |
| Tylney Ltd | Information & communication | 2023 |
| Typologie Limited | Professional & scientific | 2006 |
| Tyrer Higgins Limited | Professional & scientific | 2005 |
| Tyrolean Adventures Limited | Administrative & support | 2001 |
| Tytherton Village Hall Trading Limited | Wholesale & retail | 2019 |
| Uddin Estates Limited | Real estate | 2024 |
| Uddin Estates Property Limited | Real estate | 2025 |
| Ugesi Ltd | Professional & scientific | 2017 |
| UK Community Works CIC | Professional & scientific | 2013 |
| UK Dancewear Ltd | Wholesale & retail | 2016 |
| UK Energy Services Southern Ltd | Construction | 2020 |
| UK Private Staff Limited | Administrative & support | 2024 |
| UK Therapy Rooms Ltd | Health & social care | 2025 |
| Ukimpr Ltd | Education | 2021 |
| Ukiyo Watersports Hub Ltd | Health & social care | 2025 |
| Ukrn Services CIC | Professional & scientific | 2026 |
| Uktaxrefund Limited | Professional & scientific | 2024 |
| Ultra Performance Ltd | Professional & scientific | 2024 |
| Ultrapoint Limited | Transport & logistics | 2002 |
| Ultui Ltd | Construction | 2016 |
| UMC Industries Limited | Transport & logistics | 1957 |
| Uncle Frank's Ltd | Arts & recreation | 2024 |
| Undine Limited | Administrative & support | 2022 |