| Synchronistic Investigations (S.I.) Ltd | Administrative & support | 2025 |
| Syncro Drive Limited | Wholesale & retail | 2025 |
| Synergy Activation Ltd | Extraterritorial | 2025 |
| Synergy Influence Ltd | Extraterritorial | 2024 |
| Syntrofos Limited | Professional & scientific | 2023 |
| Szombati Ltd | Transport & logistics | 2014 |
| T & L L Construction Limited | Construction | 2021 |
| T Development Ltd | Real estate | 2022 |
| T&A Property Limited | Real estate | 2016 |
| T&B&Son Ltd | Hospitality | 2020 |
| Tagmein Ltd | Information & communication | 2025 |
| TAILORED2U Care Limited | Administrative & support | 2017 |
| Taka Construction Ltd | Construction | 2026 |
| Talking Houses Yorkshire Ltd | Real estate | 2025 |
| Talt Properties Limited | Real estate | 2024 |
| Tandoor Chai Ltd | Hospitality | 2023 |
| Tandoor Chai Takeaway Ltd | Hospitality | 2025 |
| Tank Juice Limited | Manufacturing | 2024 |
| Tankerville Trading Limited | Other services | 2024 |
| Tantalise Tanning & Beauty Ltd | Other services | 2005 |
| Tanzanite Care Solutions Ltd | Health & social care | 2020 |
| TAR Consultancy Limited | Professional & scientific | 2016 |
| Tarling Road Flat Management Company Limited | Households | 2000 |
| Tarry Close Residents Company Limited | Real estate | 2013 |
| Tarte DE Fleurs Ltd | Manufacturing | 2018 |
| TASK1 Services Ltd | Administrative & support | 2025 |
| Tasty Bitez Ltd | Hospitality | 2018 |
| TAT Trans Ltd | Transport & logistics | 2022 |
| Taverners Lodge Freehold Limited | Financial services | 2004 |
| Tax Planning Matters Limited | Financial services | 2014 |
| TBH Joinery Ltd | Manufacturing | 2025 |
| TBL Ventures Ltd | Real estate | 2025 |
| TDM Books Limited | Extraterritorial | 2012 |
| Tech Medics Repair Limited | Other services | 2023 |
| Tech Organise Ltd | Information & communication | 2018 |
| Techcity Limited | Information & communication | 1996 |
| Techeloper Limited | Information & communication | 2026 |
| Techmount IT Limited | Information & communication | 2025 |
| Teeviyah Care Limited | Health & social care | 2025 |
| Telecom Experts 2013 Limited | Information & communication | 2013 |
| Teledesign Solutions Limited | Information & communication | 2001 |
| Telegartner UK Ltd | Manufacturing | 2001 |
| Teller Creative Limited | Professional & scientific | 2022 |
| Telos and Associates Ltd | Wholesale & retail | 2022 |
| Temasek Properties Ltd | Professional & scientific | 2004 |
| Temo Group Ltd | Wholesale & retail | 2025 |
| Tempestas Omnes Doncaster Limited | Construction | 2018 |
| Tempestas Omnes Group Limited | Construction | 2018 |
| Tempestas Omnes Leeds Limited | Construction | 2018 |
| Tempestas Omnes Northampton Limited | Construction | 2018 |
| Tempestas Omnes Nottingham Limited | Construction | 2018 |
| Tempis Consultants Limited | Professional & scientific | 2014 |
| Temple Associates Consulting & Recruitment Ltd | Professional & scientific | 2007 |
| Temple Rigging Services Ltd | Information & communication | 2019 |
| Templegate Estates Limited | Real estate | 1997 |
| Temu UK Ltd | Wholesale & retail | 2026 |
| TEN TEN Resources Trustees Limited | Other services | 2026 |
| Ten-Arms Ltd | Administrative & support | 2024 |
| Tendring Hundred Water Services Limited | Extraterritorial | 1998 |
| Tengu Trade Ltd | Wholesale & retail | 2023 |
| Tennis Club Management International Limited | Professional & scientific | 1986 |
| Terra Pfeiffer Matt Durbin JV Limited | Construction | 2018 |
| Test Engine Ltd | Information & communication | 1997 |
| TF GAS and Heating Ltd | Construction | 2015 |
| TGM Construct Ltd | Construction | 2016 |
| Thai Herb Limited | Other services | 2015 |
| Thandeka and Partners Limited | Health & social care | 2025 |
| Thara Ltd | Professional & scientific | 2025 |
| THE 3 Brewers Ltd | Manufacturing | 2012 |
| THE Academy Groomers on the Green Ltd | Administrative & support | 2025 |
| THE Acorns Public Health Research Limited | Health & social care | 2009 |
| THE Alam Corporation Limited | Professional & scientific | 2022 |
| THE Arting Nooks Ltd | Arts & recreation | 2024 |
| THE Blissful Baby Expert Ltd | Other services | 2015 |
| THE Board of Professional Practice for Educational Consultants Ltd. | Public administration | 2023 |
| THE Body Parlour Limited | Other services | 2021 |
| THE Body-Mod Boutique Limited | Other services | 2025 |
| THE Brookmans Cleaning Company Ltd | Administrative & support | 2024 |
| THE Butlers Pantry Design Limited | Professional & scientific | 2025 |
| THE Byte Hub Group CIC | Arts & recreation | 2020 |
| THE Car Club by Grange Limited | Construction | 2023 |
| THE Checkmate Club Ltd | Education | 2013 |
| THE Collectors MOB Ltd | Wholesale & retail | 2025 |
| THE Creative Haus Limited | Professional & scientific | 2019 |
| THE Croft Residential Care Home Ltd | Health & social care | 2006 |
| THE Decorum Group Ltd | Health & social care | 2022 |
| THE Dessert Express Hatfield Ltd | Hospitality | 2024 |
| THE Drip Dolls Ltd | Health & social care | 2024 |
| THE Drive (Brookmans Park) Limited | Real estate | 2007 |
| THE Dutch Nursery Limited | Wholesale & retail | 1990 |
| THE Eco Arborist Limited | Administrative & support | 2023 |
| THE Elms (Luton) Management Company Ltd | Real estate | 2017 |
| THE Empire Heritage Security Limited | Administrative & support | 2026 |
| THE Empower Project Ltd | Health & social care | 2025 |
| THE English Garden Company Limited | Administrative & support | 2005 |
| THE Fitness Circle Ltd | Education | 2014 |
| THE Food Table Ltd | Hospitality | 2026 |
| THE Foundry (Cambridge) Limited | Professional & scientific | 2017 |
| THE Frequency LAB Ltd | Health & social care | 2025 |
| THE Fruit Co Ltd | Administrative & support | 2024 |