| Top Brick Investments Limited | Real estate | 2016 |
| Top Bright Industries UK Ltd | Extraterritorial | 2013 |
| Top Class Construction Ltd | Construction | 2023 |
| Top Floor Workspace Ltd | Construction | 2022 |
| Top G Engineering Ltd | Manufacturing | 2023 |
| Top Loaded Limited | Transport & logistics | 2023 |
| Top Marque Competitions Limited | Wholesale & retail | 2022 |
| Top Notch Bathrooms and Tiling Limited | Construction | 2026 |
| Top of Your Game Limited | Arts & recreation | 2013 |
| Top Pixel Limited | Information & communication | 2016 |
| Top Pizza Palace Ltd | Hospitality | 2019 |
| Top Repair Ltd | Manufacturing | 2016 |
| Top TAP Plumbing & Bathrooms Limited | Construction | 2025 |
| Top Trade Competitions Ltd | Wholesale & retail | 2025 |
| Topcroft Ltd | Real estate | 2021 |
| Topdog Accessories Limited | Wholesale & retail | 2022 |
| Topdog TCG Ltd | Wholesale & retail | 2025 |
| Topg Wings Franchises Ltd | Administrative & support | 2026 |
| Topmark Cleaning Services (2025) Limited | Administrative & support | 2025 |
| Topmode Consultants Limited | Wholesale & retail | 1993 |
| Topstorey Holdings Ltd | Real estate | 2024 |
| Topsy Stories Limited | Arts & recreation | 2018 |
| Toptips Limited | Professional & scientific | 2023 |
| TOR Financial Consulting Limited | Financial services | 2004 |
| TOR Management Services Limited | Administrative & support | 2010 |
| TOR Suntime Company Limited(The) | Households | 1984 |
| Torbay Motorcycles Limited | Wholesale & retail | 2013 |
| Toroid Technology Limited | Manufacturing | 1979 |
| Torquay Acquisition Co Ltd | Financial services | 2023 |
| Torquay Holdings Limited | Financial services | 2014 |
| Torque Scaffolding Ltd | Construction | 2015 |
| TOS Detailing Ltd | Wholesale & retail | 2025 |
| Total Access Health Limited | Health & social care | 2017 |
| Total Access Medical Diagnosis Ltd | Health & social care | 2023 |
| Total Catering Ltd | Hospitality | 2023 |
| Total CNC Solutions Limited | Manufacturing | 2007 |
| Total Food Ltd | Hospitality | 2017 |
| Total Framing Ltd | Manufacturing | 2016 |
| Total Network Technologies Limited | Information & communication | 2004 |
| Total Padel Group Ltd | Construction | 2024 |
| Total Re-Cal Calibration Service Ltd | Manufacturing | 2025 |
| Total Renewables UK Ltd | Construction | 2022 |
| Totally Construction Ltd | Construction | 2020 |
| Totally Dynamic (Franchising) Limited | Administrative & support | 2005 |
| Totally Dynamic Limited | Extraterritorial | 2006 |
| Totally Flawed CIC | Health & social care | 2023 |
| Totally Landscapes Ltd | Administrative & support | 2019 |
| Totel Norwich Ltd | Administrative & support | 2005 |
| Toucan Appliances Ltd | Manufacturing | 2016 |
| Toucan Hire Services Limited | Administrative & support | 1980 |
| Touchbase Festival Ltd | Arts & recreation | 2021 |
| Touchline Analytics Ltd | Professional & scientific | 2018 |
| Tour Trans Ltd | Construction | 2017 |
| Touring, Logistics, Crew Ltd | Arts & recreation | 2022 |
| Tovt Ltd | Wholesale & retail | 2024 |
| Tower Commercial Letting Ltd | Real estate | 2020 |
| Tower D.I.Y. Limited | Wholesale & retail | 1980 |
| Tower Fitness Boxing Events Ltd | Arts & recreation | 2022 |
| Tower Fitness Norwich Ltd | Arts & recreation | 2022 |
| Tower Hill Park Limited | Households | 2021 |
| Tower Soft Play Limited | Arts & recreation | 2025 |
| Towering Tops Limited | Construction | 2025 |
| Town Cars Banbury Ltd | Transport & logistics | 2018 |
| Town Close Educational Trust Limited | Education | 1968 |
| Town Close Properties Limited | Real estate | 2023 |
| Town House Cafe Ltd | Hospitality | 2020 |
| Town House Films Ltd | Information & communication | 2009 |
| Toy Like ME CIC | Administrative & support | 2017 |
| Toy Street Ltd | Extraterritorial | 2017 |
| Toyzapp Ltd | Wholesale & retail | 2024 |
| TP & EC Ltd | Real estate | 2024 |
| TP Fire & Security Management Ltd | Construction | 2015 |
| TP Taverns Limited | Hospitality | 2014 |
| TP Ventures Ltd | Real estate | 2016 |
| Tp-Carpentry (NFK) Ltd | Construction | 2023 |
| TPB Student Lettings Limited | Real estate | 2020 |
| TPF GAS Services Limited | Construction | 2018 |
| TPH Rentals Ltd | Real estate | 2017 |
| TPI Security Ltd | Construction | 2016 |
| TPI Utilities Limited | Construction | 2017 |
| TPR Commissioning Limited | Construction | 2014 |
| Tptracker Ltd | Information & communication | 2003 |
| TR Capital Properties Ltd | Real estate | 2025 |
| TR Electrical Contracts Ltd | Construction | 2019 |
| TR Pubs Ltd | Hospitality | 2025 |
| TRA Marketing Ltd | Professional & scientific | 2024 |
| Trace Heating Supplies Limited | Wholesale & retail | 2021 |
| Tracey Keddy & Sons Ltd | Financial services | 2026 |
| Tracey Michelle Ltd | Manufacturing | 2014 |
| Track 4 Safety Ltd | Professional & scientific | 2020 |
| Track a Parcel Investments Limited | Financial services | 2012 |
| Track a Parcel Limited | Information & communication | 2009 |
| Track and Field Supplies Ltd | Manufacturing | 2024 |
| Tracklab Events UK Ltd | Arts & recreation | 2024 |
| TRACKS4AFRICA (UK) Ltd | Information & communication | 2016 |
| Trackson Developments Limited | Financial services | 2025 |
| Traction Online Ltd | Professional & scientific | 2021 |
| Tractor & Plant Glass Limited | Wholesale & retail | 2021 |
| Tractor and Plant Glass Windscreen Services Ltd | Construction | 2021 |
| Tracy LEE Chapman Ltd | Health & social care | 2023 |