| THE Letterworks Limited | Manufacturing | 1988 |
| THE Light & Power Company Limited | Energy | 1999 |
| THE Liquidation House Ltd | Wholesale & retail | 2019 |
| THE London Drain Company Limited | Construction | 1996 |
| THE Maze Creative Studio Ltd | Information & communication | 2020 |
| THE Mindful Hikers Limited | Arts & recreation | 2024 |
| THE Newbury & District Agricultural Society | Other services | 1991 |
| THE Newbury 7 Group Limited | Transport & logistics | 2018 |
| THE Old Forge Florist Ltd | Wholesale & retail | 2021 |
| THE Open Consulting Group Limited | Information & communication | 2005 |
| THE Optimum Health Clinic Foundation | Health & social care | 2008 |
| THE Optimum Health Clinic Limited | Health & social care | 2004 |
| THE Pet Collaboration Ltd | Manufacturing | 2022 |
| THE Rush Flooring Company Ltd | Construction | 2023 |
| THE Sitings Company Limited | Information & communication | 2002 |
| THE Smoking FOX Ltd | Hospitality | 2026 |
| THE Snugg Cafe Ltd | Hospitality | 2023 |
| THE Stone Partnership Limited | Wholesale & retail | 2004 |
| THE Summer House Collection Ltd | Wholesale & retail | 2018 |
| THE Temple Gallery LLP | | 2013 |
| THE Tipsi Tipi Ltd | Other services | 2019 |
| THE Workplace Wellness Group Limited | Health & social care | 2020 |
| Therapies at Kingfisher Ltd | Other services | 2024 |
| Theterminator Ltd | Administrative & support | 2023 |
| Think Safety Limited | Professional & scientific | 2018 |
| Think Treasury Solutions Limited | Professional & scientific | 2022 |
| Thomasson Trading Limited | Real estate | 2014 |
| Thoran Retail Ltd | Wholesale & retail | 2019 |
| Thrive People Solutions Ltd | Administrative & support | 2025 |
| Tiger Blue Properties Ltd | Real estate | 2019 |
| Tilling Property Limited | Real estate | 2021 |
| Timberheat Ltd | Agriculture & fishing | 2024 |
| Time for Property Ltd | Real estate | 2021 |
| TIN TIN Holdings Limited | Hospitality | 2023 |
| Tintou Ltd | Information & communication | 2021 |
| Tjsj Property Ltd | Real estate | 2023 |
| TM Plumbing and Heating Solutions Ltd | Construction | 2021 |
| Tofica Limited | Financial services | 2025 |
| Tompkins Rygole Ltd. | Professional & scientific | 2003 |
| Tonge Project Controls Limited | Professional & scientific | 2010 |
| Top Notch Pubco Limited | Hospitality | 2017 |
| Topline Care Solutions Ltd | Health & social care | 2022 |
| Torftech R&D Limited | Professional & scientific | 2014 |
| Torftech Technologies Limited | Professional & scientific | 1982 |
| Total Chiropractic Limited | Health & social care | 2017 |
| Total Drainage Systems (South) Ltd | Administrative & support | 2020 |
| Total Drainage Systems Limited | Administrative & support | 2006 |
| Totally Theatre Productions Limited | Administrative & support | 2010 |
| Totec Tyres Limited | Wholesale & retail | 2007 |
| Touch Blue Maintenance Limited | Other services | 1996 |
| Touch Blue Telecom Limited | Extraterritorial | 2006 |
| Touch Green Limited | Information & communication | 2007 |
| Town House Interiors Ltd | Professional & scientific | 2013 |
| TP Clearances Limited | Water & waste | 2022 |
| Tp-Link UK Limited | Wholesale & retail | 2010 |
| TPP Newbury I Ltd | Manufacturing | 2025 |
| TPP Newbury Ltd | Manufacturing | 2025 |
| Traditional Rugs Ltd | Wholesale & retail | 2019 |
| Trafalgar House Properties (Malvern) Limited | Real estate | 1965 |
| Transact in a Day AI Limited | Information & communication | 2025 |
| Transformation Tech Services Limited | Information & communication | 2015 |
| Transparent Marketing Ltd | Information & communication | 2023 |
| TRI Global Limited | Wholesale & retail | 2025 |
| Tristar Measuregraph Limited | Wholesale & retail | 2022 |
| Tropical Foods & Drinks Ltd | Wholesale & retail | 2019 |
| Trousseau Limited | Wholesale & retail | 2003 |
| True Core Fit Limited | Health & social care | 2025 |
| True North Focus Limited | Information & communication | 2025 |
| Truebird Ltd | Administrative & support | 2023 |
| Trusted Finishes Ltd | Construction | 2025 |
| Ts&Lc Limited | Arts & recreation | 2015 |
| TSL Medical Services Ltd | Professional & scientific | 2024 |
| Tthatcham Healthy Well-Being Limited | Health & social care | 2022 |
| Tu's Food Supplies Ltd | Wholesale & retail | 2025 |
| Turnpike Industrial Estate Management Company Limited | Real estate | 1991 |
| Tutorplus Limited | Education | 2023 |
| Tuxchange CIC | Wholesale & retail | 2022 |
| Two Nine O Five Health Matters Ltd | Health & social care | 2008 |
| Two Thumb Grip Asia Limited | Manufacturing | 2020 |
| U17 Drivers Pathfinder Limited | Arts & recreation | 2007 |
| UFC Solutions Ltd | Professional & scientific | 2025 |
| UK Aircon Limited | Construction | 2009 |
| Ukbp Shooting Supplies Ltd | Wholesale & retail | 2024 |
| Ukda Limited | Administrative & support | 2020 |
| Ultimate Safety Consultants Limited | Professional & scientific | 2023 |
| Universal Trade and Investment Associates Limited | Wholesale & retail | 2011 |
| Unknown Brand Productions Limited | Information & communication | 2024 |
| Unlimited Creative Limited | Professional & scientific | 2024 |
| Unreal Events Ltd | Information & communication | 2021 |
| Unrret Ltd | Other services | 2026 |
| Upperlimit (UK) Limited | Financial services | 2006 |
| Uprooted Stories CIC | Other services | 2023 |
| V Engineering Limited | Wholesale & retail | 2021 |
| V Management Ltd | Transport & logistics | 2015 |
| V S Robinson & SON Limited | Construction | 1999 |
| VAL Ridgeway Injury Clinic Ltd | Health & social care | 2024 |
| Valleda Ltd | Real estate | 2012 |
| Vanillo Ltd | Manufacturing | 2020 |
| Vansittart Ltd | Wholesale & retail | 2015 |
| Vantage Business Analytics Ltd | Information & communication | 2023 |