| THE Well Balanced Centre Ltd | Health & social care | 2023 |
| THE Wellness Corner Ltd | Health & social care | 2024 |
| THE Wheatsheaf Inn Ltd | Hospitality | 2011 |
| THE Window Shutter Company Ltd | Wholesale & retail | 2012 |
| THE Wonder Years Bromley Ltd | Education | 2020 |
| THE Wonder Years Childminding Limited | Education | 2019 |
| THE Woodhouse Butchery at Home Ltd | Wholesale & retail | 2019 |
| THE Woolpack Public House Limited | Real estate | 2013 |
| THE Yellow Heart Trust | Health & social care | 2002 |
| THE Yews (Haywards Heath) Community Partnership | Other services | 2011 |
| THE Yoga Yurt Ltd | Other services | 2025 |
| Thea Tudway Therapy Ltd | Health & social care | 2025 |
| Theo Browns Revived Ltd | Other services | 2020 |
| Thewealthworks Limited | Information & communication | 1991 |
| Think Homeopathy Limited | Administrative & support | 2008 |
| Think Plutus Limited | Financial services | 2022 |
| Think Ripple Ltd | Information & communication | 2026 |
| Thinkalink Digital Limited | Education | 2018 |
| Thinkeen Global Ltd | Other services | 2023 |
| Thinking OUT of the Box Ltd | Construction | 2021 |
| Thirty SIX Business Management Ltd | Professional & scientific | 2024 |
| This Creative Works Ltd | Information & communication | 2008 |
| This Services Limited | Other services | 2021 |
| Thomas Bird Studio Ltd | Arts & recreation | 2021 |
| Thomas Henry Harry Ltd | Professional & scientific | 2018 |
| Thomson Property & Site Services Limited | Construction | 2026 |
| Thorn Property Limited | Real estate | 2002 |
| Thorndean Projects Ltd | Construction | 2018 |
| Thorne Mason Limited | Other services | 1999 |
| Thornley Management Systems Limited | Professional & scientific | 2024 |
| Thought Rebel Limited | Information & communication | 2022 |
| Threadgold Consulting Limited | Information & communication | 2017 |
| Three Cousins Estates Limited | Real estate | 2023 |
| Three Hawks Engineering Limited | Professional & scientific | 2022 |
| Three Stories Ltd | Real estate | 2023 |
| Threlco Consultants Ltd | Information & communication | 2018 |
| Threshold Editorial Limited | Information & communication | 2015 |
| Thrift Brighton Limited | Wholesale & retail | 2023 |
| Thrive Clinical Psychology and Resilience Consultancy Limited | Health & social care | 2017 |
| Thrive Pathways Ltd | Professional & scientific | 2025 |
| Throne Limited | Financial services | 2011 |
| THT Consulting Limited | Professional & scientific | 1996 |
| Thumbs UP World Limited | Education | 2016 |
| Thumwood Construction Limited | Construction | 2023 |
| Thurgood Plant Limited | Construction | 2007 |
| Tide Jewellery Limited | Wholesale & retail | 2005 |
| Tidy Digital Ltd | Information & communication | 2026 |
| Tilder Technology Limited | Information & communication | 2025 |
| TIM Griffiths Consulting Limited | Professional & scientific | 2020 |
| Time Lock'D Ltd | Arts & recreation | 2018 |
| Timelesstime Ltd | Administrative & support | 2009 |
| Timmons Consultancy Limited | Professional & scientific | 2013 |
| Timt Theatre Touring Limited | Arts & recreation | 2020 |
| Tinaw Investments Ltd | Real estate | 2019 |
| Tinny Kiddo Ltd Ltd | Health & social care | 2025 |
| Tinto Delta Ltd | Professional & scientific | 2025 |
| Tipper Advisory Services Ltd | Professional & scientific | 2013 |
| Tirul Aviation Limited | Professional & scientific | 2024 |
| Tisshaws Limited | Professional & scientific | 2012 |
| Tiwala Travel and Tour Ltd | Administrative & support | 2025 |
| TKV Property Limited | Real estate | 2021 |
| Tmate Limited | Hospitality | 2015 |
| Toad Hall Equestrian Ltd | Agriculture & fishing | 2023 |
| Toad Hall Equine Rehabilitation Ltd | Agriculture & fishing | 2023 |
| Todaymovers Limited | Transport & logistics | 2025 |
| Toggle Property Limited | Real estate | 2020 |
| Toku Sake Limited | Wholesale & retail | 2020 |
| TOM Foat Fitness Coaching Ltd | Health & social care | 2025 |
| Toni 2009 Limited | Construction | 2009 |
| Tonkin Holdings Ltd | Financial services | 2020 |
| Tonkin Ventures Ltd | Real estate | 2022 |
| Tony Smith Communications Ltd | Professional & scientific | 2020 |
| Toon World Ltd | Wholesale & retail | 2019 |
| Top Fade Barber Haywards Heath Ltd | Other services | 2024 |
| Top Grid Engineering Ltd | Energy | 2023 |
| Top Store Shop Ltd | Wholesale & retail | 2026 |
| Tophat L&D Ltd | Professional & scientific | 2019 |
| Toplets Property Services Limited | Real estate | 2010 |
| Topline Naturals (Organic) Limited | Manufacturing | 2017 |
| Topline Naturals Limited | Manufacturing | 2017 |
| Total Delivery Limited | Information & communication | 2019 |
| Totality Consulting Ltd | Professional & scientific | 2023 |
| Tower Blending Company Limited | Professional & scientific | 1946 |
| Town & Country Construction Limited | Construction | 2004 |
| Town Centre Regeneration Limited | Real estate | 2009 |
| TPA Planning & Environment Ltd | Professional & scientific | 2012 |
| Trace Medispa Ltd | Other services | 2018 |
| Trading & Links Limited | Professional & scientific | 2001 |
| Traffic Systems Limited | Information & communication | 2008 |
| Train the Way YOU Play Limited | Other services | 2020 |
| Trainair Solutions Ltd | Professional & scientific | 2016 |
| Trajan Capital Ltd | Professional & scientific | 2026 |
| Transformare Consulting Limited | Professional & scientific | 2016 |
| Transport Lines Limited | Professional & scientific | 2012 |
| Travel Radar Media Ltd | Information & communication | 2018 |
| Travel Together Limited | Administrative & support | 2021 |
| Treasury Team Limited | Professional & scientific | 2012 |
| Treehoppers FK Limited | Education | 2018 |
| Treestone Investments Limited | Real estate | 2025 |
| Tremains Farm Ltd | Agriculture & fishing | 2024 |