| T.K.Couriers and Recruitment Ltd | Transport & logistics | 2018 |
| T2I GDS Ltd | Professional & scientific | 2025 |
| Tabied Limited | Health & social care | 2021 |
| Tablecraft Limited | Administrative & support | 2009 |
| Taco UP Wings Ltd | Hospitality | 2026 |
| Tadas & Co Ltd | Construction | 2012 |
| Taggar & Shergill Estates Ltd | Real estate | 2025 |
| Tailor Made Joinery Limited | Construction | 2005 |
| Tailored Coaching Limited | Administrative & support | 2008 |
| Talavera Financial Services Ltd | Financial services | 2020 |
| Talentbook Recruitment Ltd | Administrative & support | 2022 |
| Talking Health Communities CIC | Education | 2013 |
| Talking Health Social Enterprise Network Limited | Information & communication | 2013 |
| Tall Order Limited | Professional & scientific | 1996 |
| Talmac Associates UK Ltd | Information & communication | 2011 |
| Taloglen Properties Limited | Real estate | 1976 |
| TAM Transport Limited | Administrative & support | 2017 |
| Tamyog Services Ltd | Professional & scientific | 2019 |
| Tandem Recruitment Group Ltd | Administrative & support | 2024 |
| Tanners Lane (Kettering) Ltd | Wholesale & retail | 2019 |
| Tansford Limited | Wholesale & retail | 2023 |
| Tanzanite Services Ltd | Health & social care | 2023 |
| TAP & Trade Retail Ltd | Wholesale & retail | 2025 |
| Tapcart Limited | Wholesale & retail | 2025 |
| Tapp Engineering Consultancy Ltd | Professional & scientific | 2026 |
| Tara-Lota Ltd | Households | 2026 |
| Taredewi Limited | Information & communication | 2015 |
| Tarras Park Properties (Campden Hill) Limited | Professional & scientific | 2013 |
| Tarras Park Properties Limited | Real estate | 2003 |
| Tarrpa Properties Ltd | Real estate | 2026 |
| Tarry's Kettering Loam Limited | Professional & scientific | 1960 |
| Tartan Room Productions Ltd | Information & communication | 2026 |
| Tasman Design Limited | Information & communication | 2009 |
| Taste Tracks Ltd | Hospitality | 2022 |
| Tastebridge Ltd | Wholesale & retail | 2025 |
| Tasty Gyros Ltd | Hospitality | 2025 |
| Tasty Shawrma Ltd | Hospitality | 2024 |
| Taurus Management Solutions Ltd | Administrative & support | 2011 |
| Taurus Property Improvements Ltd | Construction | 2025 |
| Tautvydasmi Ltd | Transport & logistics | 2019 |
| Taylor'D Solutions Limited | Professional & scientific | 2008 |
| TB22LOGISTICS Ltd | Transport & logistics | 2018 |
| TBS Financial Limited | Financial services | 2024 |
| TBW Group Limited | Wholesale & retail | 2026 |
| TC Haven Ltd | Wholesale & retail | 2024 |
| TC Vehicle Service's Ltd | Wholesale & retail | 2025 |
| TCK Photography Limited | Professional & scientific | 2013 |
| Tdfs Holdings Ltd | Financial services | 2018 |
| TDI 3D Creations Ltd | Manufacturing | 2024 |
| TDS Roofing Limited | Construction | 2003 |
| Teal Bidco Limited | Financial services | 2024 |
| Teal Midco 1 Limited | Financial services | 2024 |
| Teal Midco 2 Limited | Financial services | 2024 |
| Teal Topco Limited | Financial services | 2024 |
| Tech World Kettering Ltd | Wholesale & retail | 2026 |
| Techiot Ltd | Information & communication | 2019 |
| Technical Building Products Limited | Extraterritorial | 1987 |
| Technical Systems Services Ltd | Manufacturing | 2024 |
| Technoir Ltd | Information & communication | 2017 |
| Techpathway Ltd | Information & communication | 2025 |
| Techsynergy Solutions Limited | Information & communication | 2012 |
| Tectum Property Management Ltd | Real estate | 2022 |
| TED Compliance Ltd | Professional & scientific | 2019 |
| Teddy Red Limited | Wholesale & retail | 2020 |
| Tegal Transport Ltd | Transport & logistics | 2021 |
| TEJ Lettings Ltd | Real estate | 2019 |
| TEK BUA Limited | Construction | 2019 |
| TEK Solve Limited | Information & communication | 2022 |
| Tektek Ltd | Other services | 2023 |
| Telecom Services Limited | Information & communication | 1986 |
| Telford Mann Group Limited | Financial services | 2022 |
| TEN Cottages Limited | Real estate | 2017 |
| Tenan Limited | Professional & scientific | 2019 |
| Tench Logistics Limited | Transport & logistics | 2018 |
| Tenex Advisory Limited | Professional & scientific | 2023 |
| Tengrace Ltd | Health & social care | 2025 |
| Tengwe Ltd | Administrative & support | 2019 |
| Tentrait Limited | Information & communication | 2025 |
| Terilion Ltd | Information & communication | 2025 |
| Teriyaki Japanese Limited | Hospitality | 2021 |
| Terwood Limited | Professional & scientific | 2010 |
| Tesserae Communications Limited | Administrative & support | 2015 |
| Test Safe Alarms Limited | Professional & scientific | 2017 |
| TETA23 Ltd | Transport & logistics | 2015 |
| Tetrad Properties Ltd | Real estate | 2020 |
| Tetramass Limited | Manufacturing | 2011 |
| Teymuroglu Ltd | Other services | 2026 |
| TGR Garage & Transport Ltd | Wholesale & retail | 2024 |
| TGS Transport LLP | | 2016 |
| TH Rail Services Ltd | Construction | 2024 |
| TH3 Avon Ltd | Real estate | 2025 |
| Thai Retail Limited | Hospitality | 2018 |
| Thai Tana Ltd | Wholesale & retail | 2010 |
| That Gardening Company Ltd | Administrative & support | 2024 |
| That Pink Shop Ltd | Wholesale & retail | 2024 |
| That’S the Move Ltd | Transport & logistics | 2026 |
| THE Adhd Lifespan Clinic Ltd | Health & social care | 2024 |
| THE Agbalumo Company Ltd | Manufacturing | 2026 |
| THE Aggreys Limited | Transport & logistics | 2022 |
| THE Answers People Limited | Health & social care | 2020 |