| TMC Facilities Ltd | Other services | 2026 |
| TMC Motor Parts Limited | Wholesale & retail | 1995 |
| TMJ Roofing Limited | Construction | 2012 |
| TML Homes Ltd | Real estate | 2025 |
| Tmnt Consulting Limited | Professional & scientific | 2016 |
| TMS Estates Ltd | Real estate | 2020 |
| TMS Howbury Lane Ltd | Real estate | 2020 |
| TN16 Catering Co Ltd | Hospitality | 2019 |
| Tndd Ltd | Construction | 2014 |
| TNM Infinity Paints Ltd | Construction | 2025 |
| TNT Housing & Development Limited | Real estate | 2022 |
| Toba Solutions Ltd | Professional & scientific | 2023 |
| Tobiko Limited | Hospitality | 2001 |
| Tobis Holdings Ltd | Financial services | 2020 |
| Tochiz Ltd | Health & social care | 2024 |
| Toda Consulting Ltd | Information & communication | 2015 |
| Today Grace Consult Limited | Health & social care | 2016 |
| Todd Meat Trading Company Limited | Wholesale & retail | 1989 |
| Todor VAS Limited | Wholesale & retail | 2022 |
| Toff&Co Ltd | Financial services | 2015 |
| Together With Africa | Other services | 2003 |
| Togi and Ossies Barbers Ltd | Other services | 2017 |
| Togi Barber Limited | Other services | 2023 |
| Toii Consultancy Limited | Extraterritorial | 2018 |
| TOK Works CIC | Administrative & support | 2025 |
| Tokenize Properties Ltd | Real estate | 2022 |
| Tokssan Consultant Limited | Professional & scientific | 2025 |
| Tola Communications Ltd | Information & communication | 2019 |
| Tola Tiling Limited | Construction | 2015 |
| TOM & Paul PT Ltd | Other services | 2025 |
| Tomblyboo Developments Ltd | Construction | 2020 |
| Tomlinson Leigh Limited | Professional & scientific | 2017 |
| Tonbridge Sushi Ltd | Hospitality | 2022 |
| Tondina & SON Limited | Real estate | 1965 |
| Tonerace Property Management Company Limited | Administrative & support | 1992 |
| Tong XIN TAI Limited | Wholesale & retail | 2024 |
| Tonwin Management Company Limited (the) | Households | 1975 |
| Tony Marsh Limited | Other services | 2018 |
| Toolec Ltd | Construction | 2023 |
| Top Construction & Refurbishment Services Ltd | Construction | 2023 |
| Top Hygiene Ltd | Wholesale & retail | 2018 |
| Top Medics and Care Services Ltd | Health & social care | 2022 |
| Top Nails 68 Ltd | Other services | 2024 |
| Top Quality Mobile Fisheries Ltd | Hospitality | 2025 |
| Top Rank Tuition Ltd | Education | 2026 |
| Top Sports Coaching Limited | Education | 2019 |
| Top Style Hair Dresser and Beauty Ltd | Other services | 2022 |
| Topbird Coaching Limited | Professional & scientific | 2022 |
| Topbody Essential Ltd | Manufacturing | 2026 |
| Topcoat (Mast and Towers) Limited | Construction | 2015 |
| Topfix Property Limited | Real estate | 2023 |
| Topgas Ltd. | Construction | 2021 |
| Topic Music Limited | Professional & scientific | 2016 |
| Topman Rubbish Clearance Limited | Administrative & support | 2021 |
| Topserve (UK) Limited | Administrative & support | 2009 |
| Topsol Property Limited | Real estate | 2025 |
| Torotim Ltd | Wholesale & retail | 2025 |
| Toshneuman Ltd | Real estate | 2020 |
| Total Administration Group Outsourcing Limited | Professional & scientific | 2024 |
| Total Care 247 Limited | Health & social care | 2008 |
| Total Food Service Ltd | Hospitality | 2024 |
| Total RN Ltd | Health & social care | 2021 |
| Total Scaffolding (London) Limited | Construction | 2004 |
| Totally Unique Bathrooms Limited | Wholesale & retail | 2015 |
| Totsgalaxy Limited | Wholesale & retail | 2016 |
| Totti London Ltd | Hospitality | 2025 |
| Touch PR Ltd | Professional & scientific | 2005 |
| Towel Petroleum and Logistics Ltd | Manufacturing | 2021 |
| Tower Land Limited | Real estate | 2022 |
| Tower Trading Ltd | Real estate | 2019 |
| Towersite Limited | Real estate | 1999 |
| Towersite Newmarket Ltd | Real estate | 2025 |
| Town & City Homes Limited | Real estate | 2013 |
| TP Brickwork Ltd | Construction | 2018 |
| TP Cladding Ltd | Construction | 2025 |
| TPS Development Limited | Real estate | 2025 |
| TPW Property Group Ltd | Real estate | 2025 |
| TR3A Properties Limited | Real estate | 2019 |
| Tra@Nails Ltd | Other services | 2022 |
| Track Newswave Recording Limited | Information & communication | 2024 |
| TRACK365 Ltd | Wholesale & retail | 2024 |
| Trad Group Limited | Professional & scientific | 1997 |
| Trad Hire & Sales Limited | Construction | 1998 |
| Trad Scaffolding Co.Limited | Construction | 1971 |
| Trade & Prosper Ltd | Professional & scientific | 2019 |
| Trade Apps Ltd | Construction | 2017 |
| Trade Fittings Direct Ltd | Construction | 2021 |
| Trade Winds (Kent) Ltd | Wholesale & retail | 2025 |
| Tradeglobe Limited | Professional & scientific | 2022 |
| Traditional Group Ltd Ltd | Construction | 2025 |
| Tradymus Ltd | Wholesale & retail | 2025 |
| Trafalgar Developments Limited | Real estate | 1984 |
| Traffix Global Ltd | Wholesale & retail | 2025 |
| Trajan Tyres Ltd | Wholesale & retail | 2019 |
| Tramuda Ltd. | Professional & scientific | 2016 |
| Transcend Links Ltd | Health & social care | 2022 |
| Transport MA Services Ltd | Transport & logistics | 2024 |
| Transport Orient Limited | Transport & logistics | 2014 |
| Transport Repair Solutions Ltd | Manufacturing | 2024 |
| Transprop Limited | Real estate | 2020 |