| Teamdiverse Limited | Construction | 1986 |
| Teame Electrical Limited | Construction | 2015 |
| Teamland Properties Limited | Real estate | 2022 |
| Teamo Marine Safety Products Limited | Manufacturing | 2012 |
| Teamy Technologies Limited | Information & communication | 2017 |
| TEC Civils Limited | Administrative & support | 2015 |
| TEC Plumbing and Heating Ltd | Construction | 2026 |
| TEC REC Coaching Ltd | Administrative & support | 2017 |
| Tech Comrades Ltd | Wholesale & retail | 2025 |
| Tech-Stitch Recruitment Limited | Administrative & support | 2025 |
| Techforce Talent Limited | Administrative & support | 2025 |
| Techlife Services Limited | Financial services | 2024 |
| Techne Model Studio Limited | Wholesale & retail | 2021 |
| Technet Networks Ltd | Information & communication | 2011 |
| Technic Domestic Ltd | Other services | 2015 |
| Technical and Professionals Training Services Limited | Education | 2020 |
| Technical Arboriculture Limited | Professional & scientific | 2006 |
| Technical Construction Limited | Professional & scientific | 2006 |
| Technical Marine UK Limited | Professional & scientific | 2016 |
| Technical Research and Development (U.K.) Limited | Professional & scientific | 1984 |
| Technisales Ltd | Professional & scientific | 2013 |
| Technix Rubber & Plastics Limited | Manufacturing | 1989 |
| Technologies Hub (UK) Limited | Wholesale & retail | 2021 |
| Technologik Ltd | Information & communication | 2022 |
| Technology Bridge Limited | Information & communication | 2023 |
| Technoman Limited | Information & communication | 1997 |
| Techsoft and Education Consultants UK Ltd | Information & communication | 2020 |
| Techsolent C.I.C. | Information & communication | 2021 |
| Techved Consulting Limited | Information & communication | 2026 |
| Techvire Solutions Ltd | Information & communication | 2025 |
| Teco Development Ltd | Information & communication | 2022 |
| Tecord Global Limited | Wholesale & retail | 2026 |
| Tecsail Systems Ltd | Information & communication | 2008 |
| Tecserv Cleaning Equipment Services Limited | Manufacturing | 1997 |
| Ted's Fish & Chips Limited | Hospitality | 2025 |
| Tedtbear Media Ltd | Arts & recreation | 2020 |
| TEE Empower Limited | Health & social care | 2020 |
| Teektak Hire Ltd | Administrative & support | 2024 |
| Teensz Ltd | Hospitality | 2026 |
| Tegg Motor Company Limited | Wholesale & retail | 2014 |
| Tegg Properties Limited | Real estate | 2023 |
| Tegg Residentials Ltd | Real estate | 2023 |
| Tegg Stays Limited | Hospitality | 2023 |
| Tegian Properties Limited | Real estate | 2019 |
| TEJ Investments Limited | Financial services | 2025 |
| TEJ MOT & Tyres Ltd | Wholesale & retail | 2009 |
| Tejasheth Limited | Transport & logistics | 2024 |
| TEK Creations Ltd | Manufacturing | 2022 |
| Tek-Dek Limited | Wholesale & retail | 2020 |
| Tekever Ltd | Manufacturing | 2013 |
| Tekin Amca Ltd | Hospitality | 2026 |
| Tekin Catering Ltd | Hospitality | 2025 |
| Teknet Ltd | Information & communication | 1997 |
| Tekserve UK Limited | Other services | 2000 |
| Tekton Projects Ltd | Construction | 2026 |
| Telecoms Consulting Limited | Information & communication | 2006 |
| Telegraph Books Ltd | Information & communication | 2025 |
| Telegraph Estates Ltd | Construction | 2020 |
| Telegraph Heights Management Company Limited | Real estate | 2017 |
| Telegraph Property Management Limited | Real estate | 2012 |
| Telekon Reelone Ltd | Administrative & support | 2019 |
| Telematicus Limited | Information & communication | 2009 |
| Telephone House (Southampton) Management Limited | Households | 2006 |
| Telephone House Limited | Wholesale & retail | 2012 |
| Telford Smith Limited | Financial services | 2014 |
| Telhouse Holdings Limited | Financial services | 2022 |
| Tell ME a Bedtime Story Ltd. | Arts & recreation | 2013 |
| Tellspec Ltd | Information & communication | 2015 |
| Tellwright Consulting Limited | Administrative & support | 2018 |
| Telnet Screen Productions Ltd | Information & communication | 2022 |
| Templar Court (Southampton) Residents Limited | Households | 1989 |
| Temple Towers Properties Limited | Households | 1950 |
| Temple Wilson Resourcing Ltd | Administrative & support | 2020 |
| Templebrand Limited | Households | 1984 |
| Templeton Stockbridge Limited | Real estate | 2013 |
| Temporary Solutions Traffic Management Ltd | Construction | 2021 |
| Tempted Finds Ltd | Wholesale & retail | 2026 |
| Temri Limited | Information & communication | 2016 |
| Tenant Direct Ltd | Real estate | 2006 |
| Tenant Link Limited | Real estate | 2001 |
| Tenant Shop CC Limited | Administrative & support | 2016 |
| Tenant Shop Home Services Limited | Administrative & support | 2014 |
| Tenant Shop Services Limited | Information & communication | 2010 |
| Tenantfirst Lettings Limited | Real estate | 2026 |
| Tenax Vult Limited | Professional & scientific | 2013 |
| Tender Touch Pet Salon (Salisbury) Limited | Other services | 2025 |
| Tenderchange Limited | Construction | 1996 |
| Tenders Alpha Limited | Wholesale & retail | 2025 |
| Tendring Care Homes Limited | Health & social care | 2005 |
| Tennis Coaching Management Ltd | Professional & scientific | 2018 |
| Tentbox Holdings Limited | Financial services | 2016 |
| Tentbox Limited | Wholesale & retail | 2016 |
| Teo&Madalina Ltd | Transport & logistics | 2024 |
| Teranga Roots Ltd | Hospitality | 2026 |
| Teresa Holdings Limited | Other services | 2003 |
| Terra Battery UK Limited | Wholesale & retail | 2024 |
| Terra Firma Land Developments Limited | Other services | 2019 |
| Terranoa Consulting Ltd | Information & communication | 2011 |
| Terranoa Estate Limited | Real estate | 2023 |
| Terrill Properties Limited | Real estate | 2018 |