| Switch NOW Community Interest Company | Education | 2015 |
| Switch NOW Training Ltd | Education | 2021 |
| Swrb Accounts Ltd | Professional & scientific | 2026 |
| SWS Moto Tech Ltd | Wholesale & retail | 2020 |
| Swynford Coffee Ltd | Hospitality | 2026 |
| Sycal Markham Limited | Financial services | 2013 |
| Sylo Trans Ltd | Transport & logistics | 2016 |
| Symonds Wilson Properties Ltd | Construction | 2022 |
| Syncsound Family Ltd | Information & communication | 2025 |
| Synergen Group Limited | Water & waste | 2010 |
| Synergy Crew Ltd | Administrative & support | 2020 |
| Synergy Electrical Solutions Ltd | Construction | 2025 |
| Synergy Event Crew Limited | Financial services | 2021 |
| Syrah Vista Limited | Other services | 2012 |
| Szerman Ltd | Transport & logistics | 2017 |
| T & a Highways Limited | Construction | 2015 |
| T & B Law Limited | Professional & scientific | 2022 |
| T & T Property Management Ltd | Households | 2021 |
| T B Safety Consultancy Limited | Professional & scientific | 2016 |
| T J Wines Ltd | Wholesale & retail | 2002 |
| T Payne Construction Limited | Construction | 2024 |
| T S Biomass Limited | Professional & scientific | 2024 |
| T. Brown & SON (Covington) Limited | Agriculture & fishing | 1984 |
| T.E.D Systems Ltd | Administrative & support | 2009 |
| T.P.U. Ltd. | Construction | 2005 |
| T.R. West Limited | Construction | 2004 |
| T1 Trans Ltd. | Transport & logistics | 2018 |
| T4 Telecommunications Limited | Information & communication | 2018 |
| Tacconi Green & Co Limited | Professional & scientific | 1994 |
| Tackle and Bates Ltd | Wholesale & retail | 2021 |
| Taipan Property Investment Limited | Real estate | 2020 |
| Take Part OT Limited | Health & social care | 2016 |
| Talcon Ltd | Manufacturing | 2025 |
| Taliyo Ltd | Information & communication | 2013 |
| Talking Telephone Numbers Ltd | Information & communication | 1995 |
| Talle Ltd | Wholesale & retail | 2025 |
| Tallystick Consult Ltd | Information & communication | 2022 |
| Talton Property Management Limited | Construction | 2020 |
| Tamg Limited | Construction | 2015 |
| Tan&Tad Limited | Health & social care | 2013 |
| Tant Real Estate & Investments Ltd | Real estate | 2019 |
| Tapldoo Ltd | Information & communication | 2020 |
| Tappenden Baker Limited | Information & communication | 2014 |
| Tasker Insurance Group Limited | Financial services | 2010 |
| Taste Natural Ltd | Hospitality | 2019 |
| Tattersall Brickwork Ltd | Construction | 2018 |
| Tattersalls Crescent Management Company Limited | Professional & scientific | 1990 |
| TAU Sparkle Cleaners Ltd | Administrative & support | 2019 |
| Taurus Access Ltd | Administrative & support | 2024 |
| Tawicorp UK Limited | Information & communication | 2020 |
| Tayfas Ltd | Public administration | 2026 |
| Taylor Asset Holdings Ltd | Construction | 2026 |
| Taylormade Risk Services Ltd | Financial services | 2018 |
| Tbdatavidendi Limited | Information & communication | 2023 |
| Tbdg Limited | Real estate | 2023 |
| TBR Property Services Ltd | Construction | 2025 |
| TC3 & Co. Ltd | Professional & scientific | 2026 |
| TCG Trade Hub Limited | Wholesale & retail | 2026 |
| Teacher MAT PAY Limited | Administrative & support | 2025 |
| Teal Engineering Ltd. | Professional & scientific | 2015 |
| Teal Property Solutions Limited | Administrative & support | 2016 |
| Team C Properties Ltd | Construction | 2018 |
| Team C Rentals Ltd | Households | 2023 |
| Team HU Ltd | Professional & scientific | 2023 |
| Team HU Transport Ltd | Transport & logistics | 2023 |
| Team Player Solution Ltd | Information & communication | 2019 |
| Tear Repair UK Ltd | Wholesale & retail | 2005 |
| Tearoom 1905 Limited | Hospitality | 2025 |
| Tech Circuits Limited | Information & communication | 2000 |
| Techmiracle Technologies Limited | Wholesale & retail | 2009 |
| Techpro - Gadget Repair and Accessories Ltd | Manufacturing | 2025 |
| Teddy's Soft Play Limited | Administrative & support | 2019 |
| TEE Dealer Ltd | Wholesale & retail | 2022 |
| TEE1 Logistics Ltd | Transport & logistics | 2025 |
| Telescopic Commercials Ltd | Wholesale & retail | 2026 |
| Teljay Ltd | Professional & scientific | 2024 |
| Tempio Ltd | Real estate | 2024 |
| Tenison Homes Limited | Real estate | 1976 |
| Teo&Tea Ltd | Hospitality | 2024 |
| Terra Elegant Nails Ltd | Other services | 2025 |
| Terry Coffin Developments Limited | Construction | 2014 |
| Terry Coffin Properties Limited | Real estate | 2020 |
| Terry Griffith Limited | Construction | 2023 |
| Tescan-Uk Ltd. | Professional & scientific | 2013 |
| Texa Threat Solutions Ltd | Water & waste | 2019 |
| Texir Ltd | Transport & logistics | 2022 |
| Textcare Limited | Professional & scientific | 2014 |
| TFG Gardens Ltd | Administrative & support | 2025 |
| Thatchby Limited | Wholesale & retail | 2017 |
| THE 1995 4/5 High Street Huntingdon Management Company Limited | Households | 1995 |
| THE 1995 Holme (Godmanchester) Management Limited | Households | 1995 |
| THE Abbey Group Cambridgeshire Limited | Professional & scientific | 1987 |
| THE Alarm Experts UK Ltd | Administrative & support | 2019 |
| THE Angel PUB Ramsey Limited | Hospitality | 2025 |
| THE Architectural Designer Studio Limited | Professional & scientific | 2017 |
| THE Attic by DH CIC | Wholesale & retail | 2021 |
| THE Barbers DEN (Cambs) Ltd | Other services | 2017 |
| THE Bateman Brown Trustees Limited | Real estate | 2024 |
| THE Bengal Bristol Ltd | Wholesale & retail | 2024 |
| THE Bengal Ltd | Hospitality | 2022 |