| Tangible Biosciences Ltd | Wholesale & retail | 2025 |
| Tanner KSP Limited | Professional & scientific | 2011 |
| Tannery Consulting Ltd | Professional & scientific | 2023 |
| Tannery Court Residents Management Limited | Households | 2009 |
| Tanning Centre (Kingston) Limited | Other services | 1997 |
| Tanson Collective Limited | Real estate | 2026 |
| Tantrum Music 2020 Ltd | Information & communication | 2021 |
| Tantrum Music LLP | | 2014 |
| Tara House Limited | Construction | 2013 |
| Taraxx Ltd | Other services | 2024 |
| Tarbet Tree Care Ltd | Agriculture & fishing | 2020 |
| Tarosa Ltd. | Financial services | 2020 |
| Tartech Ltd | Professional & scientific | 2018 |
| Tartinya Fitzgerald Ltd | Administrative & support | 2013 |
| TAS Aerials Limited | Information & communication | 2017 |
| Tasca Cafe Ltd | Hospitality | 2021 |
| Tasquier Enterprises Ltd | Real estate | 2026 |
| Taste of 9JA Kitchen Ltd | Hospitality | 2025 |
| Tattam's Coffee Ltd | Wholesale & retail | 2022 |
| Tattams Ltd | Hospitality | 2017 |
| Taur Technologies Limited | Manufacturing | 2019 |
| Taurus Construction and Supplies Ltd | Construction | 2023 |
| Tavistock Financial Services Limited | Financial services | 1997 |
| Taylor Made Computer Solutions Limited | Information & communication | 2019 |
| Taylor Made Uniforms Limited | Wholesale & retail | 2009 |
| Taylored Room Designs Limited | Professional & scientific | 2022 |
| Taywell Limited | Real estate | 2020 |
| Taywood Engineering Limited | Construction | 2025 |
| TB Richardson Holdings Limited | Real estate | 2019 |
| TB Richardson Ltd | Professional & scientific | 2002 |
| TCG Online Ltd | Wholesale & retail | 2026 |
| Tcg-Maker Ltd | Manufacturing | 2025 |
| Teachbeyond | Education | 2014 |
| Teal Stag Property Ltd | Real estate | 2026 |
| Team LBD Dressage Ltd | Administrative & support | 2015 |
| Teapro Limited | Hospitality | 2018 |
| Teasdale’S Electrical Services Ltd | Construction | 2018 |
| Teazelcat Ltd | Information & communication | 2018 |
| Tebbutt Engineering Ltd | Professional & scientific | 2025 |
| Tebsolutions Ltd | Information & communication | 2023 |
| Tech Assistant Ltd | Other services | 2012 |
| Tech Spark Consulting Limited | Information & communication | 2021 |
| Techbeau Limited | Wholesale & retail | 2025 |
| Technical DC Services Ltd | Professional & scientific | 2024 |
| Technical Grip Services Limited | Administrative & support | 2003 |
| Technical Pets Limited | Professional & scientific | 2019 |
| Techniques for Change Limited | Education | 2001 |
| Technology Control Solutions Limited | Information & communication | 2001 |
| Technology Experts International Ltd | Information & communication | 2022 |
| Technology Partnership (UK) Ltd | Information & communication | 2014 |
| Techs Consult Security Limited | Administrative & support | 2013 |
| Tecta Build Ltd | Construction | 2022 |
| Tecta Homes Ltd | Real estate | 2022 |
| Teddington Tanning Centre Limited | Other services | 2005 |
| Tekdips Ltd | Professional & scientific | 2025 |
| Tekk CBS Limited | Construction | 2010 |
| Telecom Acquisitions Ltd | Financial services | 2019 |
| Telecom UK Ltd | Information & communication | 2008 |
| Telecoms Online UK Limited | Wholesale & retail | 2017 |
| Temp Home Solutions Ltd | Administrative & support | 2024 |
| Tempo Clothing UK Ltd | Wholesale & retail | 2025 |
| Temsho Konsult Limited | Real estate | 2024 |
| TEN Wise MEN Limited | Extraterritorial | 2015 |
| Tender Ritual Limited | Manufacturing | 2025 |
| Terra Firma Fire and Security Ltd | Administrative & support | 2022 |
| Terra Sure Drives & Patios Ltd | Administrative & support | 2025 |
| Terrabyte Limited | Information & communication | 2014 |
| Terragrow Ltd | Wholesale & retail | 2020 |
| Teutonics Ltd | Wholesale & retail | 2018 |
| Tfdousters Ltd | Construction | 2025 |
| TFY Plumbing and Maintenance Ltd | Construction | 2021 |
| TG Cando Limited | Professional & scientific | 2017 |
| TH Risk Solutions Limited | Professional & scientific | 2017 |
| TH4TS3CUR1TY.COMPANY Ltd | Professional & scientific | 2019 |
| Thai Sensations Limited | Other services | 2024 |
| Thakeham Village Football Club Ltd | Arts & recreation | 2016 |
| Thalatta Consulting Ltd | Professional & scientific | 2023 |
| Thames Electrical Limited | Construction | 2002 |
| Thames Luxury Cruises Limited | Transport & logistics | 2025 |
| That Speech Lady Ltd | Health & social care | 2021 |
| Thatcher Maritime Consultancy Ltd | Transport & logistics | 2023 |
| Thatframe Limited | Information & communication | 2005 |
| THE Adviser Support Hub Limited | Financial services | 2005 |
| THE Affordable Events Company Ltd | Administrative & support | 2016 |
| THE ALL Star Property Company Limited | Real estate | 2016 |
| THE Angelic Host Ltd | Hospitality | 2023 |
| THE Aries Partnership LLP | | 2020 |
| THE Arnold Consultancy Ltd | Information & communication | 1998 |
| THE Augusta Film Limited Liability Partnership | | 2003 |
| THE Bathgate Forge Ltd | Arts & recreation | 2021 |
| THE Beauty Studio (Sussex) Ltd | Other services | 2025 |
| THE BED Centre Bramley Limited | Wholesale & retail | 2003 |
| THE Billington Partnership Limited | Construction | 2016 |
| THE Blind Co.Com Ltd. | Extraterritorial | 2000 |
| THE Blue Mile Limited | Professional & scientific | 2003 |
| THE Bolenowe Terrace Management Company Limited | Households | 2026 |
| THE Born Free Foundation | Other services | 1998 |
| THE Branded Lender Limited | Professional & scientific | 2004 |
| THE Braybrooke Beer Company Limited | Manufacturing | 2017 |
| THE CA Brand Ltd | Information & communication | 2011 |