| Tomium Technology Ltd | Professional & scientific | 2022 |
| Tomy Construction Ltd | Construction | 2014 |
| Tony 2018 Limited | Administrative & support | 2021 |
| Tony Johnstone Golf Limited | Administrative & support | 2009 |
| Tony's Technical Engineers Ltd | Construction | 2025 |
| Toof Consult Ltd | Administrative & support | 2017 |
| Toolan Management Services Limited | Professional & scientific | 2008 |
| Toolroom Technology Limited | Information & communication | 1988 |
| Toolset Ltd | Information & communication | 2020 |
| Toozs Company Limited | Administrative & support | 2011 |
| Top 4CS Ltd. | Wholesale & retail | 2009 |
| Top Brothers Limited | Hospitality | 2021 |
| Top Dog Advisory & Consulting Ltd | Professional & scientific | 2022 |
| Top Grillz Ltd | Hospitality | 2023 |
| Top Nails 8 Ltd | Other services | 2026 |
| Top of Range Vans Ltd | Wholesale & retail | 2013 |
| Top of the Mops Bucks Ltd | Administrative & support | 2025 |
| Top of the Totz Ltd | Education | 2024 |
| Top UK Trade Ltd | Real estate | 2022 |
| Top-Np Education Centre Ltd | Professional & scientific | 2019 |
| Top-Np Property Ltd | Real estate | 2025 |
| Topical Pharma Limited | Professional & scientific | 2016 |
| Topkare Limited | Administrative & support | 2016 |
| Topline Provider Ltd | Health & social care | 2014 |
| Tops Pizza Aylesbury Limited | Hospitality | 2021 |
| Topspeks Motors Limited | Wholesale & retail | 2024 |
| TOR Graith Limited | Professional & scientific | 2015 |
| Torque Performance HQ Ltd | Wholesale & retail | 2025 |
| Torque Precision Limited | Manufacturing | 2019 |
| Tors Equestrian Limited | Manufacturing | 2021 |
| Tortoiseshell Holdings Limited | Manufacturing | 2024 |
| Tortuga Bay Holdings Ltd | Information & communication | 2024 |
| Tosca Property and Lettings Limited | Real estate | 2021 |
| Total 360 Healthcare Ltd | Public administration | 2023 |
| Total Driving Limited | Other services | 2011 |
| Total Finance Management Limited | Professional & scientific | 2025 |
| Total Fireworks Limited | Wholesale & retail | 2002 |
| Total Format Digital Ltd | Professional & scientific | 2022 |
| Total Freedom Tabernacle Ministries | Other services | 2012 |
| Total Geomatics Limited | Administrative & support | 2017 |
| Total Human Resources Limited | Professional & scientific | 2006 |
| Total Kitchen Ltd | Wholesale & retail | 2025 |
| Total Lawn Care TLC Limited | Administrative & support | 2020 |
| Total Medics Limited | Professional & scientific | 2013 |
| Total Prestige Ltd | Professional & scientific | 2007 |
| Total Pyro Limited | Arts & recreation | 2006 |
| Total Tyres South Ltd | Manufacturing | 2023 |
| Total Vitality Ltd | Professional & scientific | 2012 |
| Total Water Limited | Construction | 2022 |
| Toti Construction Ltd | Construction | 2023 |
| Toto's Pizza Ltd | Hospitality | 2026 |
| Touch Technologies Limited | Information & communication | 2015 |
| Touchline Payroll Ltd | Professional & scientific | 2026 |
| Touchstone Bathrooms Limited | Administrative & support | 2013 |
| Touricom Ltd | Administrative & support | 2018 |
| Towd Mobile Tyres Ltd | Wholesale & retail | 2025 |
| Towersey Electricity Limited | Real estate | 2013 |
| Townend (Steeple Aston) Management Company Ltd | Households | 2021 |
| Townfir Property Management Limited | Professional & scientific | 1989 |
| Township Tattoo Ltd | Arts & recreation | 2022 |
| Toy Haul Ltd | Wholesale & retail | 2021 |
| Toylinn Ltd | Wholesale & retail | 2022 |
| TP Services Ltd | Transport & logistics | 2024 |
| TP Smart Repairs Ltd | Wholesale & retail | 2019 |
| TP3 Global Limited | Manufacturing | 2012 |
| TRA Nest Care Ltd | Health & social care | 2025 |
| Tracer Finance Limited | Financial services | 2022 |
| Track Four Consulting Limited | Professional & scientific | 2008 |
| Trackside Competitions Ltd | Extraterritorial | 2024 |
| Traction Central Ltd | Information & communication | 2013 |
| Trade Mark Agencies Ltd | Wholesale & retail | 2019 |
| Trade Square Plumbing & Heating Supplies Ltd | Wholesale & retail | 2025 |
| Trade Windows and Supplies Limited | Wholesale & retail | 1994 |
| Traded Life Tenancies Limited | Administrative & support | 2007 |
| Trades Warehouse Ltd | Wholesale & retail | 2020 |
| Tradespro Ltd | Construction | 2021 |
| Tradris Consultancy Limited | Professional & scientific | 2020 |
| Traffic Matters Group Limited | Information & communication | 2020 |
| Trailblazer Crew Limited | Professional & scientific | 2025 |
| TRAILER4U Limited | Wholesale & retail | 2024 |
| Train Like Champions Ltd | Education | 2024 |
| Tranquility Energy Limited | Energy | 2019 |
| Transaction International Limited | Transport & logistics | 1986 |
| Transcamera Limited | Transport & logistics | 1999 |
| Transform Consulting Limited | Professional & scientific | 2022 |
| Transition Video Limited | Information & communication | 2015 |
| Transport B & B Ltd | Transport & logistics | 2017 |
| Transport CRS Ltd | Transport & logistics | 2023 |
| Transport SM Limited | Transport & logistics | 2017 |
| Transworld Operations Ltd | Professional & scientific | 2024 |
| Treasure Bay Limited | Wholesale & retail | 2015 |
| Treasured City CIC | Education | 2023 |
| Treasured One Ltd | Health & social care | 2021 |
| Treasured Personnel Limited | Administrative & support | 2022 |
| Treble One Consulting Limited | Information & communication | 2025 |
| Treend Sets Ltd | Manufacturing | 2023 |
| Treharne Building Consultancy Limited | Professional & scientific | 2011 |
| Trek Wireless Limited | Information & communication | 2004 |
| Trent Bess I Limited | Energy | 2024 |
| Trent Bess III Limited | Energy | 2021 |