| Techinpro Limited | Information & communication | 2017 |
| Techne Studio Ltd | Wholesale & retail | 2025 |
| Techno Help Ltd | Professional & scientific | 2023 |
| Technovation (Conference Production Management) Limited | Other services | 1992 |
| Techrev Global Growth Partners Ltd | Other services | 2024 |
| Techsolis Limited | Information & communication | 2024 |
| TED & George Cleaning Services Limited | Administrative & support | 2023 |
| TED Does Zoomies Ltd | Wholesale & retail | 2025 |
| TED Munson Ltd | Professional & scientific | 2019 |
| Teddington Lion Limited | Hospitality | 2025 |
| Teddy Partners Limited | Professional & scientific | 2025 |
| Teena Williams Limited | Other services | 2008 |
| Teetotal Ltd | Manufacturing | 2011 |
| Tejx Limited | Professional & scientific | 2026 |
| Tekdox Ltd | Information & communication | 2013 |
| Tekfx Digital Ltd. | Information & communication | 2011 |
| Tekly Solutions Ltd | Information & communication | 2026 |
| Tekoi Consulting Ltd | Information & communication | 2022 |
| Tellybox Productions Limited | Information & communication | 2010 |
| Tember Corporation Limited | Education | 2003 |
| Temeraire Place Residents Management Company Limited | Households | 2003 |
| Temple Projects Ltd | Construction | 2018 |
| TEN Tudor Road Residents (Freehold) Limited | Households | 2002 |
| TEN Tudor Road Residents (Kingston) Limited | Households | 1973 |
| Tenantcare Solutions Ltd | Real estate | 2025 |
| Tenet Design (Contracts) Limited | Other services | 1994 |
| Tennis Services UK Limited | Administrative & support | 2005 |
| Tennyson Place Management Co. Limited | Households | 1992 |
| TEP Electrical Services Limited | Construction | 2009 |
| Teramu Consulting Ltd | Professional & scientific | 2023 |
| Teraplex Limited | Professional & scientific | 2023 |
| Terra Nova CP Limited | Financial services | 2024 |
| Terry New Denture Clinic Ltd | Health & social care | 2026 |
| Tesentials Ltd | Information & communication | 2024 |
| Test Teach Limited | Education | 2008 |
| Texmodel Limited | Wholesale & retail | 2011 |
| Tfts (UK) Limited | Professional & scientific | 1998 |
| TG Controls Ltd | Construction | 2022 |
| TG Maintenance Ltd | Construction | 2019 |
| TGF Electrical Contractors Limited | Construction | 2025 |
| TGG Bespoke Ltd | Other services | 2023 |
| THA Traders Ltd | Wholesale & retail | 2025 |
| Thai on Thames Kingston Limited | Hospitality | 2018 |
| Thaihouse Market V Ltd | Hospitality | 2024 |
| Thames Ditton Flooring Ltd | Construction | 2021 |
| Thames Grange Management Limited | Households | 1970 |
| Thames Haven Management Company (Kingston) Limited | Households | 1974 |
| Thames Heron Limited | Real estate | 2023 |
| Thames Reach (Hampton) Management Limited | Households | 1997 |
| Thames View (Kingston) Management Limited | Households | 1995 |
| Thameside Trustees Limited | Financial services | 2023 |
| Thameswoodliving Ltd | Real estate | 2025 |
| That Product Fellow Limited | Administrative & support | 2022 |
| That's Wild Ltd | Professional & scientific | 2025 |
| Thaxton Services Limited | Professional & scientific | 1998 |
| THE Advice GAP Limited | Professional & scientific | 2021 |
| THE Alderstone Group Ltd | Administrative & support | 2024 |
| THE Alexandra Park Sports Club (Trading) Limited | Arts & recreation | 2024 |
| THE Alexandra Park Sports Club CIC | Education | 2022 |
| THE Art History Laboratory Limited | Professional & scientific | 2024 |
| THE Associates Limited | Administrative & support | 2022 |
| THE Association of Traditional Chinese Medicine and Acupuncture UK | Other services | 1996 |
| THE Avant-Garde Art Research Project Ltd | Education | 2014 |
| THE Azar Building Company Limited | Construction | 2003 |
| THE Barn Coffee Roasters UK Limited | Manufacturing | 2024 |
| THE Basu Group UK Ltd | Other services | 2019 |
| THE Better Brand Ltd | Professional & scientific | 2026 |
| THE Boat House Company Limited | Real estate | 1996 |
| THE Boat House Residents Company Limited | Real estate | 1994 |
| THE Brecons Management Limited | Households | 1997 |
| THE Burgundy International Limited | Transport & logistics | 2019 |
| THE Calder Theatre Bookshop Limited | Arts & recreation | 2011 |
| THE Centre for Teams LLP | | 2025 |
| THE Charcoal People Limited | Wholesale & retail | 2007 |
| THE Cheeky PEA Catering Ltd | Wholesale & retail | 2019 |
| THE Chef Table Ltd | Hospitality | 2024 |
| THE Chess Valley Project Ltd | Construction | 2023 |
| THE Chosen Future Group Limited | Administrative & support | 2020 |
| THE Church Welfare Association (Incorporated) | Health & social care | 1910 |
| THE Clean Laundry Ltd | Other services | 2023 |
| THE Cloche HAT Ltd. | Real estate | 1989 |
| THE Clock House Group Limited | Hospitality | 2016 |
| THE Clock House Restaurant Property Company Limited | Administrative & support | 2010 |
| THE Clockhouse Wimbledon Limited | Households | 2009 |
| THE Coaching House Limited | Education | 2020 |
| THE Compleat Dish Ltd | Hospitality | 2023 |
| THE Corporate Escape Club Limited | Extraterritorial | 2022 |
| THE Cosmos People's ORG Ltd | Other services | 2020 |
| THE Couple Therapist Limited | Health & social care | 2026 |
| THE Creativespa Limited | Professional & scientific | 2020 |
| THE Curve W5 (RTM) Company Limited | Households | 2020 |
| THE Cutfather Thames Limited | Other services | 2026 |
| THE Dental Lounges London Limited | Health & social care | 2021 |
| THE Dental Lounges Wimbledon Limited | Health & social care | 2021 |
| THE Disability Sports Network CIC | Professional & scientific | 2023 |
| THE Diving Academy Limited | Administrative & support | 2010 |
| THE Dome Sweden Ltd | Hospitality | 2024 |
| THE Drive (Coombe) Company Limited | Households | 2016 |
| THE EDI Place Ltd | Professional & scientific | 2024 |
| THE Egyptian Cultural Heritage Organisation | Information & communication | 1998 |