| T.L.Jones Ltd | Hospitality | 2025 |
| T.R. Parsons Ltd | Wholesale & retail | 2016 |
| T.S.C. Music Systems Limited | Manufacturing | 1975 |
| T13BKL Ltd | Hospitality | 2024 |
| T3D3 Ltd | Professional & scientific | 2017 |
| TA Consult Partners Ltd | Professional & scientific | 2011 |
| TA Innovative Waste Solutions Ltd | Water & waste | 2006 |
| TAC House Spartan Ltd | Arts & recreation | 2014 |
| Tack Global Ltd | Professional & scientific | 2008 |
| Tack Industries Limited | Administrative & support | 1954 |
| Tack International Limited | Professional & scientific | 1994 |
| Tack Management Consultants Limited | Professional & scientific | 1961 |
| Tack Sales and Marketing Training Limited | Professional & scientific | 1996 |
| Tack TMI UK Limited | Professional & scientific | 2019 |
| Tack Training Worldwide Limited | Administrative & support | 1969 |
| Tactical Fabrics Ltd | Wholesale & retail | 2021 |
| Tadcaster Computers Ltd | Information & communication | 2024 |
| TAE Property Limited | Real estate | 2025 |
| TAF Chesterfield Ltd | Manufacturing | 2017 |
| Tagme Ltd | Information & communication | 2012 |
| Takita Properties Ltd | Real estate | 2021 |
| Talar-Made Limited | Manufacturing | 2002 |
| Talking Balloons Ltd | Manufacturing | 2019 |
| TAM Intelligence Ltd | Information & communication | 2026 |
| Tamesis Digital Limited | Information & communication | 2009 |
| Tammy's Luxury Hire Ltd | Transport & logistics | 2023 |
| TAN & Glow Chesterfield Ltd | Other services | 2024 |
| TAN 2 Go Ltd | Other services | 2018 |
| TAN Runner Limited | Other services | 2026 |
| Tanasher Ltd | Health & social care | 2018 |
| Tanfield Trading Medical Services Ltd | Health & social care | 2024 |
| Tangtalk Education Ltd | Professional & scientific | 2026 |
| Tank Solutions Ltd | Administrative & support | 2015 |
| Tantus H&S Ltd | Administrative & support | 2025 |
| Tanyard Properties Limited | Construction | 2016 |
| Tanzone (Yorkshire) Ltd | Other services | 2018 |
| Tanzone 2 Limited | Other services | 2023 |
| TAP House Brewery Ltd | Hospitality | 2021 |
| Tapewell (Property) Limited | Real estate | 1983 |
| Tapton Surfacing Limited | Construction | 2025 |
| Tapton Valeting Limited | Wholesale & retail | 2021 |
| Tapvenus Ltd | Hospitality | 2025 |
| Target Construction Services Limited | Construction | 1998 |
| Target Physio Injection Ltd | Health & social care | 2025 |
| Targitai Ltd | Manufacturing | 2022 |
| Tarma Engineering Limited | Manufacturing | 2018 |
| TAS88 Ltd | Health & social care | 2026 |
| Taste of KPK Ltd | Hospitality | 2026 |
| Tatstu Limited | Other services | 2013 |
| Taurus Northern Services Limited | Transport & logistics | 2019 |
| Tavla Limited | Hospitality | 2023 |
| Tawnywood (Avenue) Limited | Professional & scientific | 1996 |
| Tawnywood (Hotels) Limited | Hospitality | 1997 |
| Tawnywood Holdings Limited | Professional & scientific | 2021 |
| Tawnywood Limited | Real estate | 1990 |
| Tawnywood Recycling Limited | Water & waste | 2014 |
| Taxicover (U.K.) Ltd | Transport & logistics | 1997 |
| Taylor Holmwood Limited | Construction | 2011 |
| Taylor IP Holdings Ltd | Professional & scientific | 2018 |
| Taylormade GAS Solutions Ltd | Arts & recreation | 2024 |
| Taylormade Roofing & Construction Ltd | Construction | 2026 |
| Taymac Engineering Limited | Manufacturing | 2010 |
| TB Electrical Services Ltd | Construction | 2018 |
| TBA (Chesterfield) Ltd | Hospitality | 2022 |
| TBG Group Solutions Limited | Financial services | 2014 |
| TBG Solutions Limited | Information & communication | 2001 |
| Tbhc & Training Ltd | Health & social care | 2021 |
| TBP Industrial Limited | Wholesale & retail | 2025 |
| TC Motorcycles Ltd | Wholesale & retail | 2021 |
| TC Security Holdings Limited | Financial services | 2020 |
| TC Suburban Living Ltd | Real estate | 2026 |
| TC Surveys Limited | Other services | 2022 |
| Tcsc Solutions Ltd | Information & communication | 2021 |
| TCW Creative Services Ltd | Arts & recreation | 2013 |
| TDL Construction Services Limited | Construction | 2018 |
| TDW Ltd | Professional & scientific | 2017 |
| Teach - Hair Education Limited | Education | 2021 |
| Teach US on Tour Ltd | Education | 2025 |
| Teacher Tech AI Limited | Information & communication | 2025 |
| Teal Ventures Limited | Real estate | 2010 |
| Tealehealth Ltd | Professional & scientific | 2023 |
| TEB Railconsult Limited | Professional & scientific | 2026 |
| TEC4 Limited | Extraterritorial | 2015 |
| TEC4 Lubricants Ltd | Wholesale & retail | 2012 |
| Tech CPR Limited | Other services | 2014 |
| Tech for Techs Group Ltd | Information & communication | 2022 |
| Tech Novum Limited | Wholesale & retail | 2026 |
| Tech Station Limited | Information & communication | 2008 |
| TECH4 Motorsport Limited | Arts & recreation | 2007 |
| Techman Engineering Ltd. | Extraterritorial | 1990 |
| Technical Utilities Services (UK) Limited | Construction | 2007 |
| Technically Safe Limited | Professional & scientific | 2022 |
| Technique Learning Ltd | Education | 2021 |
| Technology for Industry Limited | Professional & scientific | 1992 |
| Technologyhelp Limited | Information & communication | 2003 |
| Techroute Global Ltd | Information & communication | 2025 |
| Teckf Limited | Information & communication | 2025 |
| Tecnosole Sales (UK) Ltd | Wholesale & retail | 2019 |
| TED Hayward Ltd | Construction | 2025 |
| Tedd Engineering Limited | Professional & scientific | 1991 |