| T.J Cole Consultancy Limited | Professional & scientific | 2022 |
| T.J. Lodge Opticians Limited | Wholesale & retail | 2004 |
| T.Mistry & Associates Limited | Professional & scientific | 2018 |
| T.S. & Williams Automobiles Limited | Wholesale & retail | 2013 |
| T.S. Forster & Sons Limited | Professional & scientific | 1906 |
| T.Sweetmap Ltd | Administrative & support | 2017 |
| T2 Enterprises (UK) Ltd | Transport & logistics | 2013 |
| T2V Solutions Ltd | Information & communication | 2023 |
| T3BUOR Professional Services Ltd | Transport & logistics | 2026 |
| T3CKA Technologies Ltd | Information & communication | 2020 |
| TA Building & Housing Limited | Construction | 2024 |
| TA Nails 04 Limited | Other services | 2025 |
| TA Solutions Limited | Information & communication | 2023 |
| Ta-Da! ALL Done Ltd | Administrative & support | 2025 |
| Taago Ltd | Manufacturing | 2007 |
| TAB Software Ltd | Information & communication | 2025 |
| Tabio (UK) Ltd | Other services | 2018 |
| Table Seven Limited | Hospitality | 2017 |
| Table Tennis England Limited | Arts & recreation | 2014 |
| Tabs Enterprise Ltd | Health & social care | 2024 |
| TABUL8 Limited | Information & communication | 2021 |
| Tabwood Limited | Wholesale & retail | 2010 |
| TACK24 Ltd | Wholesale & retail | 2019 |
| Tactical Advisory Solutions Ltd | Information & communication | 2019 |
| Tactical Vanguard Ltd. | Manufacturing | 2025 |
| Tactus Estate and Asset Management Limited | Real estate | 2016 |
| Tadman Investments Ltd | Real estate | 2020 |
| Tady Ventures Ltd | Wholesale & retail | 2021 |
| Taff Engineering Ltd | Manufacturing | 2015 |
| Tafman Limited | Health & social care | 2016 |
| Tafnet Logistics Limited | Transport & logistics | 2019 |
| Tafta Holdings Limited | Real estate | 2020 |
| TAG a Friend Limited | Wholesale & retail | 2013 |
| TAGM2 Limited | Financial services | 2023 |
| Tahira Mini Market Limited | Wholesale & retail | 2021 |
| TAI Media Limited | Information & communication | 2021 |
| TAI YAU UK Limited | Households | 2020 |
| Taikibe Limited | Public administration | 2024 |
| Tail-Fin Asset Management Limited | Information & communication | 2025 |
| Tailored Pest Control Limited | Administrative & support | 2017 |
| Taim's Store Limited | Wholesale & retail | 2025 |
| Tairicky Properties Ltd | Real estate | 2025 |
| Tairicky Solutions Limited | Professional & scientific | 2014 |
| Taisheng Trade Ltd | Wholesale & retail | 2025 |
| Tait and SON Ltd | Wholesale & retail | 2017 |
| Tait-Elan Limited | Information & communication | 2025 |
| Taiyotek Limited | Information & communication | 2026 |
| TAJ Barber Shop Ltd | Other services | 2026 |
| TAJ Company (UK) Ltd | Wholesale & retail | 2018 |
| Tajideen Ltd | Wholesale & retail | 2018 |
| Takaishi UK Company Limited | Wholesale & retail | 2023 |
| Takawira-Sarah Limited | Health & social care | 2022 |
| Take ME to the Moon Ltd | Other services | 2023 |
| Takeback Limited | Wholesale & retail | 2000 |
| Takpea Healthcare Services Limited | Public administration | 2020 |
| Takubox Ltd | Wholesale & retail | 2025 |
| Tala Languages Limited | Information & communication | 2026 |
| Talbot Court (Woolstone Q Milton Keynes) Limited | Households | 1993 |
| Talent Advance Limited | Professional & scientific | 2013 |
| Talent Evolution Consulting Ltd | Professional & scientific | 2020 |
| Talent Innovations Limited | Information & communication | 2000 |
| Talent Next Consulting Services Ltd | Information & communication | 2021 |
| Talent Works International Ltd | Professional & scientific | 2009 |
| Taliana Creative Ltd | Hospitality | 2025 |
| Talicoaching Ltd | Education | 2025 |
| Talix Search Limited | Administrative & support | 2025 |
| Talk of the Town Live Limited | Extraterritorial | 2005 |
| Talking Point Counselling Limited | Health & social care | 2023 |
| Talksgpt AI Ltd | Information & communication | 2025 |
| Tallas Consultancy Limited | Information & communication | 2025 |
| Tallo Limited | Professional & scientific | 2019 |
| Talqon Limited | Information & communication | 2023 |
| Tama Marketing Ltd | Transport & logistics | 2019 |
| Tamai Technologies Ltd | Information & communication | 2025 |
| Tame Your Garden Ltd | Administrative & support | 2019 |
| Tamhair Group Ltd | Other services | 2024 |
| Tami Transport Services Ltd | Transport & logistics | 2019 |
| Tamilsuvai Ltd | Hospitality | 2024 |
| Tammy Louise Ltd | Wholesale & retail | 2025 |
| Tamore Limited | Real estate | 2024 |
| Tan-Tastic (Milton Keynes) Limited | Other services | 2003 |
| Tana Care Ltd | Health & social care | 2023 |
| Tanase Recruitment Ltd | Administrative & support | 2021 |
| Tanatomy Limited | Administrative & support | 2002 |
| Tandice Property Ltd | Real estate | 2021 |
| Tandooridesichai Limited | Hospitality | 2023 |
| Tang Cheng International Finance Ltd | Professional & scientific | 2021 |
| Tangent Inspired Ltd | Wholesale & retail | 2025 |
| Tangent Solutions Ltd | Administrative & support | 2001 |
| Tangerine Platform Limited | Arts & recreation | 2021 |
| Tango Check Ltd | Administrative & support | 2023 |
| Tanlux Ltd | Other services | 2019 |
| Tannya Limited | Health & social care | 2014 |
| Tansley House Properties Limited | Construction | 2020 |
| Tanta Limited | Transport & logistics | 2017 |
| Tantech Solutions Limited | Information & communication | 2024 |
| Tantek Digital Solutions UK Limited | Professional & scientific | 2021 |
| Tantram Property Development Ltd | Real estate | 2021 |
| Tantrum Entertainment Group Ltd | Information & communication | 2015 |
| Tanveer Limited | Wholesale & retail | 2023 |