| Thornton Avenue Freehold Limited | Households | 2019 |
| Thorogood Advisory Group Ltd | Professional & scientific | 2026 |
| Those Boxing Brothers Ltd | Arts & recreation | 2023 |
| Three Oranges Limited | Wholesale & retail | 2019 |
| Three Sixty Investments NO1 Limited | Financial services | 2018 |
| Three Valley Care Ltd | Health & social care | 2024 |
| THREE6TEE Virtual Tours Ltd | Professional & scientific | 2024 |
| Thrive People Ltd | Real estate | 2014 |
| Thurmutis Property Limited | Real estate | 2025 |
| TIA and Mummy Cakes Ltd | Manufacturing | 2025 |
| TIA Group Limited | Construction | 2021 |
| Tia-Mya Limited | Other services | 2018 |
| Ticco Foods Holdings Limited | Financial services | 2013 |
| Tickle Community Limited | Administrative & support | 2021 |
| Tickle Place Limited | Real estate | 2022 |
| Tickle Technical Limited | Professional & scientific | 2016 |
| Tidesoveya Ltd | Wholesale & retail | 2025 |
| Tigaro Ltd | Wholesale & retail | 2026 |
| Tiger Global Group Limited | Arts & recreation | 2025 |
| Tiger Trophies Limited | Wholesale & retail | 2018 |
| Tigergate Ltd | Wholesale & retail | 2020 |
| Tile Art Limited | Construction | 2010 |
| Tillack Limited | Information & communication | 2006 |
| Tillack SPV Ltd | Real estate | 2022 |
| TIM Builders Limited | Construction | 2016 |
| TIM Pollitt Ltd | Information & communication | 2025 |
| Tim's Carpentry Ltd | Construction | 2025 |
| Time Critical Worldwide Limited | Transport & logistics | 2015 |
| Timothy Road Limited | Real estate | 2024 |
| Tiny Muddy Boots Ltd | Health & social care | 2017 |
| Tiny Talisman Games Limited | Arts & recreation | 2017 |
| Tiny Toez Pre-School Ltd | Education | 2013 |
| TIP Top Golf Limited | Arts & recreation | 2025 |
| Tips Haulage Ltd | Transport & logistics | 2016 |
| Tiptop Competitions Ltd | Wholesale & retail | 2026 |
| Tish Trading Limited | Wholesale & retail | 2024 |
| Titan Mercantile Ltd | Wholesale & retail | 2026 |
| Titan Trade Hub Ltd | Wholesale & retail | 2025 |
| Titan Transport Production Ltd | Transport & logistics | 2025 |
| Titanium Care Ltd | Construction | 2022 |
| Tite Street, Chelsea Management Company Limited | Households | 2026 |
| Tj's Food (UK) Limited | Hospitality | 2016 |
| Tj's Tricks & Training Ltd | Administrative & support | 2024 |
| TJM Developments Limited | Construction | 2017 |
| Tkdfalcons Ltd | Education | 2024 |
| TKG Consultants Ltd | Professional & scientific | 2020 |
| TLC (Reading) Ltd | Health & social care | 2022 |
| TLC (Wales) Independent Fostering Limited | Health & social care | 2003 |
| TLC (Wembley) Ltd | Other services | 2018 |
| TLC Athena Aesthetics Limited | Health & social care | 2022 |
| TLC England Limited | Health & social care | 2025 |
| TLC Knightsbridge Ltd | Other services | 2016 |
| TLC Rejuvenate Ltd | Other services | 2017 |
| Tlcg Limited | Other services | 2015 |
| TM Consultation (UK ) Ltd | Professional & scientific | 2023 |
| TM Heating & Plumbing Services Limited | Construction | 2013 |
| TM Pro-Drive Limited | Education | 2022 |
| TMA Housing Limited | Real estate | 2025 |
| Tmac Infra Limited | Real estate | 2024 |
| TMF Marketing Services Limited | Professional & scientific | 2010 |
| TMT Property & Developments Ltd | Construction | 2022 |
| TO the END Studios Ltd | Information & communication | 2026 |
| TO the Rock Limited | Arts & recreation | 2018 |
| Toad Towing and Engineering Ltd | Wholesale & retail | 2018 |
| Tobley Limited | Real estate | 2024 |
| Together Property Developments Limited | Real estate | 2023 |
| Toggle Software Ltd | Information & communication | 2023 |
| Tollring Limited | Professional & scientific | 2009 |
| Tomalex Consulting Ltd | Construction | 2011 |
| Tomar's Medical Limited | Real estate | 2016 |
| Tombuilding.London Ltd | Construction | 2019 |
| Tomhaggard Construction Ltd | Construction | 2017 |
| Tomo Motor Group Ltd | Professional & scientific | 2015 |
| Tomo Parts Limited | Wholesale & retail | 1999 |
| Tomo Prestige Limited | Wholesale & retail | 2011 |
| Tomo Property Company Limited | Real estate | 2018 |
| Toms & Wood (Lettings) Limited | Real estate | 2019 |
| Tonamic Ltd | Information & communication | 2024 |
| Tony and Louise Limited | Information & communication | 2013 |
| Tony Contractors Ltd | Construction | 2020 |
| Tony Enterprises Ltd | Transport & logistics | 2013 |
| Tootal Textiles Holdings Limited | Extraterritorial | 1899 |
| Tootal Textiles International Limited | Extraterritorial | 1946 |
| Top E-Comm Ltd | Wholesale & retail | 2023 |
| Top Flight Recruitment Ltd. | Administrative & support | 1978 |
| Top Hill Developers Ltd | Construction | 2018 |
| Top Mobile Tyres Limited | Wholesale & retail | 2024 |
| Top Wall Construction Ltd | Construction | 2023 |
| Topcleaning GB Limited | Administrative & support | 2008 |
| Topland Property Services Hackney Ltd | Construction | 2019 |
| Topland Property Services Limited | Construction | 2016 |
| Toplus Auto Garage Limited | Wholesale & retail | 2024 |
| Toppsy Hair Ltd | Wholesale & retail | 2024 |
| Torex Precision Engineering Ltd. | Manufacturing | 2002 |
| Tornado 6 Limited | Real estate | 1996 |
| Tornado FM Ltd | Administrative & support | 2018 |
| Tornado Group International Ltd | Real estate | 2017 |
| Tosrifa Textile and Clothing Ltd | Wholesale & retail | 2022 |
| Tosrifa Trading Ltd | Professional & scientific | 2022 |
| TOT (Thirty-Four) Limited | Extraterritorial | 1957 |