| Streetwise Digital Marketing Limited | Administrative & support | 2017 |
| Strike IT Limited | Financial services | 2011 |
| Strike IT Organisation Community Interest Company | Wholesale & retail | 2021 |
| Stroeblind Ltd | Extraterritorial | 2021 |
| Sub-Zero Installations Limited | Professional & scientific | 2019 |
| Subterrain Archaeology Limited | Administrative & support | 2026 |
| Sude Events Ltd | Hospitality | 2018 |
| Suffield House Management Limited | Professional & scientific | 2002 |
| Suja Trading Ltd | Wholesale & retail | 2023 |
| Sun Life & Spirit Ltd | Extraterritorial | 2021 |
| Sunflower PE19 Ltd | Hospitality | 2024 |
| Superluminal Solutions Ltd | Professional & scientific | 2021 |
| Support 4 FUN Limited | Health & social care | 2009 |
| Surjit Singh 1 Limited | Wholesale & retail | 2024 |
| Swan Land Promotions LLP | | 2025 |
| Swig Wallet Limited | Financial services | 2019 |
| Swiss Drylining Ltd | Construction | 2021 |
| Sx-Ac Ltd | Professional & scientific | 2023 |
| Sycamore Close (Eaton Socon) Management Company Limited | Households | 2013 |
| Sync Build Ltd | Construction | 2017 |
| Sync Construction Ltd | Construction | 2020 |
| Sync Homes Ltd | Real estate | 2024 |
| Sync Running Club Ltd | Education | 2025 |
| Synerglo Ltd | Other services | 2023 |
| Synergy Grill International Limited | Manufacturing | 2017 |
| Synergy Grill Limited | Manufacturing | 2013 |
| Systemware Europe Limited | Information & communication | 2000 |
| Szponar Ltd | Other services | 2015 |
| T D House Ltd | Wholesale & retail | 2021 |
| T J Sparks Limited | Construction | 2016 |
| T&D Talent Ltd | Professional & scientific | 2026 |
| T.E.A. Consultants Limited | Professional & scientific | 2013 |
| T24 Electrical Ltd | Construction | 2025 |
| Tackwood Services Limited | Wholesale & retail | 2003 |
| Tailored Accounting Ltd | Professional & scientific | 2019 |
| Takeaway-Stneots Ltd | Information & communication | 2020 |
| Tancho Consulting Ltd | Professional & scientific | 2025 |
| Tanco Retail Ltd | Other services | 2025 |
| Tangible Support Services Ltd | Administrative & support | 2018 |
| Taurho Tutors Limited | Education | 2020 |
| Tay's Barber Ltd | Other services | 2021 |
| Tayberry Construction Limited | Construction | 2013 |
| Taylor Construction & Building Ltd | Construction | 2014 |
| Taylor James Stephens Ltd | Professional & scientific | 2017 |
| Taylor LA Madrugada Developments Limited | Real estate | 2026 |
| Tcan Solutions Limited | Professional & scientific | 2024 |
| TD Structures Limited | Professional & scientific | 2024 |
| Teamstudio Europe Limited | Information & communication | 1998 |
| Teamstudio Group Limited | Information & communication | 1999 |
| Tech Recruits Here to Connect Ltd | Administrative & support | 2024 |
| TECH13 Ltd | Information & communication | 2018 |
| Technic Service Ltd | Wholesale & retail | 2020 |
| Techno Tuition Ltd | Education | 2011 |
| Technology Gateway Services Ltd | Professional & scientific | 2020 |
| Techtonic Software Ltd | Information & communication | 2013 |
| Techwizard Limited | Other services | 2012 |
| Tecray Limited | Professional & scientific | 2004 |
| TEE to Green Limited | Professional & scientific | 1997 |
| Tehnomedia Ltd | Other services | 2018 |
| Tekmeka International Ltd | Health & social care | 2016 |
| Temple Looms Ltd | Wholesale & retail | 2025 |
| Tensor Machinery Ltd | Manufacturing | 2019 |
| Tensor PLC | Manufacturing | 1998 |
| Tensor Time and Energy LLP | | 2011 |
| Tenyo Shibu CIC | Arts & recreation | 2025 |
| Testing Coder Ltd | Information & communication | 2025 |
| TGA Transportation Ltd | Transport & logistics | 2026 |
| Thatch Barn (Yelling) Limited | Agriculture & fishing | 2016 |
| THE Antique Marketing Company Ltd | Professional & scientific | 2022 |
| THE Bell GT Paxton Ltd | Hospitality | 2020 |
| THE Best of ST Neots Ltd | Information & communication | 2022 |
| THE Biltong Boys Limited | Manufacturing | 2003 |
| THE Black Maternal Advocate Ltd | Professional & scientific | 2026 |
| THE Blooming Collection Ltd | Wholesale & retail | 2023 |
| THE Bush Inn (Crosstown) Limited | Hospitality | 2024 |
| THE Cambridge Photo Booth Ltd | Professional & scientific | 2022 |
| THE Cambridgeshire Card Show Ltd | Administrative & support | 2026 |
| THE Cambridgeshire Hunter Limited | Hospitality | 2023 |
| THE Chaii Hubs Ltd | Hospitality | 2022 |
| THE Chicken Shed Van Ltd | Hospitality | 2023 |
| THE Chipper FOX Company Limited | Administrative & support | 2023 |
| THE Content Marketing Association Limited | Other services | 2009 |
| THE Craft Shelf Ltd | Wholesale & retail | 2025 |
| THE Currency Store Limited | Financial services | 2018 |
| THE Diamond Learning Partnership Trust | Education | 2012 |
| THE Digital Shopper Consultancy Limited | Professional & scientific | 2024 |
| THE Döner House Ltd | Hospitality | 2025 |
| THE Eco Therapy Limited | Wholesale & retail | 2023 |
| THE Empire House of Beauty Limited | Health & social care | 2016 |
| THE Escape House Ltd | Wholesale & retail | 2024 |
| THE Estate Agent Coach Limited | Professional & scientific | 2013 |
| THE Finance Doctor Limited | Professional & scientific | 2014 |
| THE FOX Inn (2025) Ltd | Hospitality | 2012 |
| THE Framery Limited | Wholesale & retail | 2008 |
| THE Fudge CAN Limited | Manufacturing | 2014 |
| THE Global Investment Corporation Limited | Financial services | 2018 |
| THE Granary Management Company (Ackerman) Limited | Households | 2022 |
| THE Greatest People Ltd | Information & communication | 2026 |
| THE Happy Kids Club Limited | Other services | 2026 |
| THE Keys 118 8 Limited | Professional & scientific | 2023 |