| THE Tree House Premier Child Care Limited | Education | 2011 |
| THE Twine Group Ltd | Real estate | 2020 |
| THE Upturned Cauldron Limited | Manufacturing | 2021 |
| THE Van Rental Company Ltd | Administrative & support | 2026 |
| THE Vehicle Wrapping Academy Limited | Education | 2022 |
| THE Venue Boxing Gym Limited | Other services | 2017 |
| THE Watch Nest Limited | Wholesale & retail | 2022 |
| THE WAX Queen Limited | Wholesale & retail | 2008 |
| THE WIG Gallery Ltd | Other services | 2022 |
| THE Windmills Property Management Limited | Households | 2023 |
| THE Window MAN (Essex) Limited | Construction | 2001 |
| THE Windowman (Holdings) Ltd | Financial services | 2019 |
| THE Woodland Ministry of Outdoor Education Limited | Education | 2014 |
| THE Woods Housing Ltd | Real estate | 2024 |
| THE88STUDIOS Ltd | Information & communication | 2025 |
| Theatretrain Brentwood Limited | Arts & recreation | 2024 |
| Thebeachhouse Ltd | Hospitality | 2025 |
| Thecoverden Limited | Wholesale & retail | 2016 |
| Thelteam Ltd | Construction | 2023 |
| Themasticcompany Ltd | Construction | 2017 |
| Theobald Gold Properties Limited | Real estate | 2024 |
| Theobalds Business Park Management Company Limited | Households | 2022 |
| Theobalds Investments Limited | Financial services | 2023 |
| Theos Drive Limited | Transport & logistics | 2016 |
| Therapy With ME Ltd | Education | 2025 |
| Theresa and Sons Ltd | Health & social care | 2023 |
| Thermagenix Insulation Limited | Construction | 2023 |
| Thesizzle Ltd | Administrative & support | 2015 |
| Things Made Public CIC | Arts & recreation | 2014 |
| Think Dwellings Ltd | Real estate | 2022 |
| Think Holdings Ltd | Financial services | 2024 |
| Thinktank HR Consultancy Ltd | Administrative & support | 2017 |
| Thirsty Cups Ltd | Hospitality | 2010 |
| Thirty Four Leigh Road Limited | Households | 2014 |
| This IS ME Boutique Limited | Wholesale & retail | 2023 |
| Thmcc Ltd | Professional & scientific | 2013 |
| Thomas Building & Landscapes (UK) Limited | Construction | 2023 |
| Thomas Jansson & Partners Ltd. | Information & communication | 2019 |
| Thomas REN Associates Limited | Administrative & support | 2017 |
| Thompson Welding Limited | Construction | 2014 |
| Thompson's (Barnet) Limited | Construction | 1958 |
| Thornton and Deitz Ltd | Other services | 2018 |
| Thorpe - Dalton Limited | Other services | 2024 |
| Thorpe Bay Fisheries Limited | Agriculture & fishing | 2007 |
| Thorpe Community Services Limited | Transport & logistics | 2022 |
| Three Cord Group Limited | Professional & scientific | 2024 |
| Three E Cctv Ltd | Administrative & support | 2020 |
| Three Lakes Cattery Limited | Other services | 2018 |
| Three Peaks Holdings Limited | Other services | 2021 |
| Three P’S Promotions Limited | Administrative & support | 2024 |
| Three Rivers Golf & Country Club Limited | Arts & recreation | 2002 |
| Three Zone Ltd | Wholesale & retail | 2026 |
| Threefold Architecture Limited | Professional & scientific | 2009 |
| Threesyps Limited | Wholesale & retail | 2026 |
| Thriftwood (Victors Crescent) Management Co. Limited | Administrative & support | 1984 |
| Thriftwood Park (Brentwood) Management Company Limited | Households | 1990 |
| Throttle & Trade Collectables Ltd | Wholesale & retail | 2026 |
| Thurgoods Limited | Wholesale & retail | 1961 |
| Thurrock Amateur Boxing Club CIC | Other services | 2024 |
| Thurrock Electrical Fire & Security Limited | Construction | 2013 |
| Thurrock Property Maintenance Ltd | Construction | 2020 |
| Thuza Ltd | Health & social care | 2012 |
| Tiburon Estates Limited | Construction | 2002 |
| Ticktalkies Ltd | Information & communication | 2024 |
| Ticudeanu Trans Limited | Transport & logistics | 2018 |
| Tigersoft Limited | Information & communication | 2026 |
| Tikvah Solutions CIC | Hospitality | 2024 |
| Tilar (UK) Limited | Transport & logistics | 1990 |
| Tile Palace Ltd. | Construction | 2019 |
| Tileworx UK Limited | Construction | 2019 |
| TIM Levy Productions Limited | Arts & recreation | 2018 |
| Timbergreen Limited | Manufacturing | 2025 |
| Timberlog Lane Ltd | Hospitality | 2022 |
| Time Lift Specialists Ltd | Construction | 2024 |
| Time Scaffolding Solutions Ltd | Construction | 2015 |
| Timeless Beauty Aesthetics Limited | Other services | 2024 |
| Times Mechanic Ltd | Manufacturing | 2023 |
| Timesco Healthcare Limited | Manufacturing | 1997 |
| Timmins Property Services Limited | Construction | 2011 |
| Timms Group Ltd | Professional & scientific | 2015 |
| Timu Global Limited | Wholesale & retail | 2021 |
| Tina's Hair Salon Ltd | Other services | 2025 |
| Tiny Adventures Softplay Ltd | Health & social care | 2025 |
| TIP Top Firestop Ltd | Construction | 2026 |
| TIS Oras Ltd | Hospitality | 2017 |
| Titan Contracting Ltd | Construction | 2022 |
| Titan Drainage Solutions UK Ltd | Water & waste | 2025 |
| Titan Training Academy Limited | Professional & scientific | 2022 |
| Tithe Care Ltd | Health & social care | 2022 |
| TIV & Spice Ltd | Wholesale & retail | 2025 |
| TJS Group Ltd | Real estate | 2016 |
| TK Decorative Plastering Ltd | Construction | 2026 |
| TK Power Ltd | Construction | 2008 |
| TKT Express Limited | Transport & logistics | 2026 |
| TLC Health Care Services Ltd | Health & social care | 2022 |
| TLM Management Limited | Water & waste | 2009 |
| TLM Recycling Limited | Extraterritorial | 2016 |
| TLM Scrap Metal Limited | Extraterritorial | 2023 |
| TMC Concrete Service Ltd | Manufacturing | 2025 |
| TMF Incrementum Limited | Construction | 2020 |