| THE Infrastructure Network Limited | Professional & scientific | 2010 |
| THE Juice Smith Exec Ltd | Manufacturing | 2026 |
| THE Life MAP Foundation | Professional & scientific | 2012 |
| THE Life MAP Trading Ltd | Professional & scientific | 2020 |
| THE Listing Marketing Company Limited | Professional & scientific | 2017 |
| THE Little Morrison Company Ltd | Administrative & support | 2023 |
| THE Manor Barn Harlton Limited | Hospitality | 2019 |
| THE Mowbray Residents Management Company Limited | Households | 2000 |
| THE Music Training Exchange Ltd | Arts & recreation | 2025 |
| THE Nest Royston Ltd | Manufacturing | 2022 |
| THE OCD Doctor Ltd | Health & social care | 2023 |
| THE Old Barnshop Limited | Wholesale & retail | 2018 |
| THE Pipeline Growth Company Limited | Information & communication | 2024 |
| THE Players Hub Ltd | Education | 2025 |
| THE Pure Bicycle Company Limited | Manufacturing | 2008 |
| THE Red COW PUB (Chrishall) Ltd | Hospitality | 2023 |
| THE Rogate Group Limited | Professional & scientific | 2022 |
| THE Rosie Property Company Ltd | Real estate | 2026 |
| THE Royston Jockey Ltd | Hospitality | 2026 |
| THE Royston Plumbing & Heating Company Ltd | Construction | 2019 |
| THE Sincere Promise Consultancy Limited | Professional & scientific | 2014 |
| THE Smith Life Group Ltd | Financial services | 2026 |
| THE Social Care Network Limited | Health & social care | 2010 |
| THE ST John Lofts Management Company Limited | Households | 1997 |
| THE Sweet People Limited | Manufacturing | 1998 |
| THE Treasure Loft Ltd | Wholesale & retail | 2025 |
| THE Unity Coach Ltd | Professional & scientific | 2024 |
| THE Wedding Collection Limited | Information & communication | 2025 |
| THE Wendy House Day Nursery Impington Limited | Education | 2010 |
| THE Worshipful Company of Woolmen Sustainability Start-Up & Innovation Fund Limited | Professional & scientific | 2021 |
| THE Wyndhams Management Company Ltd | Households | 2017 |
| Therfield Chapel | Other services | 2022 |
| Thermo MET Ltd | Manufacturing | 2015 |
| Theta That Ltd | Information & communication | 2014 |
| THF Therapy Limited | Other services | 2012 |
| This IS the Tonic Limited | Wholesale & retail | 2023 |
| Thomas Electrical Limited | Construction | 1986 |
| Thomas James EUR Limited | Wholesale & retail | 2019 |
| Thompson Plumbing and GAS Ltd | Construction | 2024 |
| Thorn Learning Ltd | Information & communication | 2022 |
| Thornhill Lets Limited | Real estate | 2026 |
| Thoroughbred Studios Ltd | Information & communication | 2018 |
| Three Foot Gauge Railway Society Limited | Transport & logistics | 1994 |
| Three Geese Ltd | Wholesale & retail | 2020 |
| Thriplow Green MAN Ltd | Hospitality | 2012 |
| Thriplow Holdings Limited | Professional & scientific | 2001 |
| Thru the Letterbox Limited | Administrative & support | 2010 |
| Tide and Flow Ltd | Professional & scientific | 2026 |
| Tide Wellness Limited | Other services | 2024 |
| Tiga Europe Limited | Construction | 2007 |
| Tikgrowth Ltd | Wholesale & retail | 2024 |
| Tile Haven Royston Ltd | Wholesale & retail | 2025 |
| Tillions Limited | Wholesale & retail | 2016 |
| Tim’S Chimneys Ltd | Administrative & support | 2024 |
| Tinyworld Global Ltd | Financial services | 2016 |
| Tioluwani Food Hub Ltd | Hospitality | 2025 |
| Titux Ltd | Financial services | 2020 |
| TKR Tahir Khan Restaurant Ltd | Hospitality | 2024 |
| TMB Advisory Ltd | Professional & scientific | 2020 |
| TMN Events Limited | Information & communication | 2025 |
| Tmva UK Ltd | Professional & scientific | 2011 |
| TO Baby and Beyond Limited | Education | 2010 |
| Tobin Roofing Limited | Construction | 2007 |
| Tojagic Estates Ltd | Real estate | 2021 |
| Tokara Solutions Limited | Administrative & support | 2011 |
| Tollington Associates Limited | Professional & scientific | 2011 |
| Tomkys Services Ltd | Information & communication | 2014 |
| Tong & an Prospect LLP | | 2021 |
| Tony Skinner Limited | Administrative & support | 2024 |
| Top Tier Flooring Ltd | Construction | 2026 |
| Topo Consulting Limited | Professional & scientific | 2021 |
| Toro Corporate Finance Ltd | Extraterritorial | 2015 |
| Toucan 2 Limited | Construction | 2002 |
| Toucan Sales Solutions Limited | Information & communication | 2018 |
| Tourmalet Partners Limited | Professional & scientific | 2018 |
| Town and Gown Events Limited | Hospitality | 2024 |
| Town House Publishing Limited | Information & communication | 2007 |
| Town&Gown Coffee Cambridge Ltd | Wholesale & retail | 2019 |
| Townfield Close Shared Areas Management Company Limited | Households | 2021 |
| Toxobio Ltd | Professional & scientific | 2024 |
| Trade Exchange Crypto Limited | Wholesale & retail | 2025 |
| Trademark Eagle Limited | Administrative & support | 2012 |
| Trademark Installations Ltd | Extraterritorial | 2010 |
| Trademark Kitchens Direct Ltd | Extraterritorial | 2011 |
| Trademark Kitchens Limited | Construction | 2007 |
| Trail Riders Warehouse Limited | Wholesale & retail | 2020 |
| Tranquility Marketing Limited | Other services | 2017 |
| TRANS4MATIVE Limited | Professional & scientific | 2020 |
| Transenna Properties Limited | Households | 2001 |
| Transenna Works Management Co. Limited | Households | 2000 |
| Treasure Cache Ltd | Wholesale & retail | 2021 |
| Tredinnick Farm Barns Management Company Ltd | Professional & scientific | 2012 |
| Trends Salon Ltd | Other services | 2022 |
| Trevor Dann's Company Limited | Administrative & support | 2010 |
| Tri-My-Landscapes Ltd | Administrative & support | 2023 |
| Trienergi Ltd | Construction | 2025 |
| Trihardy Ltd | Professional & scientific | 2015 |
| Trinity Gardens Limited | Administrative & support | 2008 |
| Tron Consultancy Ltd | Financial services | 2019 |
| True Blue Limited | Other services | 2009 |