| Titan & Phoenix Properties Ltd | Real estate | 2024 |
| Titan Assist Recovery & Replacement Ltd | Transport & logistics | 2024 |
| Titan Business Consultancy Limited | Wholesale & retail | 2023 |
| Titan Diamond Limited | Professional & scientific | 2000 |
| Titan Prestige Car Club Ltd | Administrative & support | 2024 |
| Titan Procare Ltd | Manufacturing | 2025 |
| Titan Property Solutions Ltd | Real estate | 2024 |
| Titan Truck Commercial Limited | Wholesale & retail | 2024 |
| Tiyu Consulting Ltd | Real estate | 2020 |
| TJ Car Cosmetics Ltd | Wholesale & retail | 2026 |
| TJD Group Ltd | Construction | 2021 |
| Tjdisplays Ltd | Construction | 2020 |
| Tjmb Ltd | Health & social care | 2020 |
| Tjmd Construction Limited | Construction | 2025 |
| Tkit Properties Ltd | Real estate | 2021 |
| TLR Building Services Ltd | Construction | 2025 |
| TLT Property Services & Vehicles Ltd | Construction | 2023 |
| TLW Developments Limited | Construction | 2018 |
| TM FOX Holdings Limited | Extraterritorial | 2024 |
| TM Green Group Ltd | Administrative & support | 2023 |
| TM Hair Solutions Ltd | Other services | 2024 |
| TMA Management Limited | Professional & scientific | 2021 |
| TMC Landscapes & Build Ltd | Administrative & support | 2022 |
| Tmec UK Ltd. | Wholesale & retail | 2001 |
| Tmnt Limited | Information & communication | 2015 |
| TMP Rail & Civil Engineering Ltd | Construction | 2022 |
| TMP Tax Ltd | Extraterritorial | 2022 |
| TN Food Corporation Ltd | Hospitality | 2025 |
| TN Property Services Limited | Real estate | 2018 |
| Tnarg Properties Limited | Real estate | 2018 |
| TNB International Ltd | Professional & scientific | 2023 |
| TND Communications Ltd | Professional & scientific | 2014 |
| Tndc Limited | Construction | 2009 |
| TNS Consultancy Ltd | Professional & scientific | 2013 |
| TNT Tree Care Limited | Administrative & support | 2015 |
| Tnwc Holdings Limited | Financial services | 2021 |
| Tnwc Limited | Professional & scientific | 2021 |
| TO Have & to Holed Limited | Arts & recreation | 2023 |
| Tobex Integrated Consulting Limited | Professional & scientific | 2025 |
| Tobillion Chemicals Limited | Extraterritorial | 2022 |
| Todo Enterprises Ltd | Wholesale & retail | 2023 |
| Together FM Limited | Construction | 2022 |
| Tokinchain UK Ltd | Information & communication | 2025 |
| Tollgate Farms Limited | Agriculture & fishing | 2016 |
| TOM Beck Ltd | Administrative & support | 2025 |
| TOM Currigan Limited | Real estate | 1978 |
| TOM Gilbert Limited | Extraterritorial | 2018 |
| TOM Hartley JNR Limited | Wholesale & retail | 2008 |
| TOM Hartley JNR Storage Ltd | Transport & logistics | 2026 |
| TOM Haynes Consulting Limited | Professional & scientific | 2025 |
| TOM Leonard Services Ltd | Education | 2021 |
| TOM Love Ltd | Professional & scientific | 2025 |
| TOM Walker Ltd | Administrative & support | 2024 |
| TOM Youngman LL Limited | Arts & recreation | 2021 |
| Tomari Capital Limited | Financial services | 2025 |
| Tomlin Bell Limited | Health & social care | 2012 |
| Tomlinsons Cars Ltd | Wholesale & retail | 2016 |
| Tommie Gleed Hair Ltd | Other services | 2024 |
| Tommy J Properties Limited | Real estate | 2022 |
| Tom’S Electrical Services Ltd | Construction | 2023 |
| Tongston Limited | Real estate | 2008 |
| Tonguestone (Moat Farm) Ltd | Construction | 2007 |
| Tonks Group Holdings Limited | Financial services | 2026 |
| Tonks Medical Ltd | Health & social care | 2011 |
| Tonksy Treatments Limited | Health & social care | 2021 |
| Tonne E Panna (Consulting ) Limited | Wholesale & retail | 2022 |
| Tony Elvery Consultancy Ltd | Professional & scientific | 2017 |
| Tony Lalor Property Maintenance Ltd Limited | Construction | 2013 |
| Tony Thomas Consulting Limited | Professional & scientific | 2021 |
| Tony's Automotive Services Ltd | Wholesale & retail | 2025 |
| TOO Hoarse Limited | Information & communication | 2014 |
| Tool Production & Design Co Limited | Manufacturing | 1997 |
| Tooling International Limited | Manufacturing | 1986 |
| Toot Lane (Boston) Limited | Construction | 2023 |
| Top BIN World Ltd | Wholesale & retail | 2026 |
| Top Brass Entertainment Ltd | Information & communication | 2026 |
| Top HAT and Tail Limited | Construction | 1995 |
| Top Nails Salon Ltd | Other services | 2021 |
| Top Range Motors Limited | Wholesale & retail | 2012 |
| Top Tipis Ltd | Administrative & support | 2019 |
| Top-Tec Holdings Limited | Manufacturing | 2008 |
| Topaz Property Group Ltd | Construction | 2002 |
| Topcare (West Midlands) Limited | Other services | 2000 |
| Topcat Rigging Ltd | Arts & recreation | 2025 |
| Topping Property Limited | Extraterritorial | 2021 |
| Topvizio Ltd | Information & communication | 2023 |
| Torbrun Limited | Professional & scientific | 2012 |
| Torken Ltd | Manufacturing | 2025 |
| Torquehaus Motors Ltd | Wholesale & retail | 2026 |
| Torren Properties (Holdings) Limited | Extraterritorial | 2016 |
| Torren Properties Limited | Real estate | 1979 |
| Tosaturn Dental Ltd | Health & social care | 2023 |
| Total EMC Products Limited | Manufacturing | 2012 |
| Total Extract Management Limited | Administrative & support | 2015 |
| Total Player Development Ltd | Education | 2025 |
| Total QA Limited | Professional & scientific | 2010 |
| Total Value Contracting Ltd | Professional & scientific | 2014 |
| Totec Limited | Construction | 2025 |
| Tottenham Hale Properties Ltd | Real estate | 2019 |
| Totteridge Place Residents Company Limited | Households | 2017 |