| Suffolk Property Investments Limited | Real estate | 2012 |
| Suffolk Sales Ltd | Wholesale & retail | 2026 |
| Suffolk Sign Installation Ltd | Professional & scientific | 2017 |
| Suffolk Smart Repairs Ltd | Wholesale & retail | 2020 |
| Suffolk Steel Stockholders Holding Company Limited | Financial services | 2026 |
| Suffolk Steel Stockholders Limited | Wholesale & retail | 1980 |
| Suffolk Tree Services Limited | Agriculture & fishing | 2002 |
| Suffolk Whippy Limited | Hospitality | 2025 |
| Suffolk Woodcraft Ltd | Wholesale & retail | 2013 |
| Sugar Blossom Bakes Ltd | Wholesale & retail | 2025 |
| Sultan Kebab Limited | Hospitality | 2018 |
| Sumner and Tulloch Construction Limited | Construction | 2021 |
| Sunrise Sporting Limited | Wholesale & retail | 2016 |
| Sunset Cocktails Ltd | Wholesale & retail | 2020 |
| Sunshine and Green Limited | Agriculture & fishing | 2017 |
| Supreme Bangla Ltd | Hospitality | 2019 |
| Surgent Productions Ltd | Information & communication | 2019 |
| Surgent Studios Ltd | Financial services | 2018 |
| Surina Ventures Ltd | Wholesale & retail | 2023 |
| Sustainable Business Media Ltd | Information & communication | 2024 |
| Sustainable Hemp and Lime Construction Company Ltd | Construction | 2015 |
| Sutherland SET Design Limited | Administrative & support | 2011 |
| SW Accountancy Limited | Professional & scientific | 2009 |
| Swai Investments Limited | Real estate | 2002 |
| Swain Plastering Services Limited | Construction | 2022 |
| Swallows Oak Residents Association Limited | Households | 1991 |
| Swan Decorators Limited | Construction | 2005 |
| Swatercolour Ltd | Arts & recreation | 2023 |
| Switch to Sun Ltd | Construction | 2025 |
| Swonderful Rights Limited | Information & communication | 2017 |
| Swonnells Court (Lowestoft) Limited | Households | 1987 |
| Syed Group Holdings Limited | Financial services | 2019 |
| T & L (Holdings) Limited | Financial services | 2008 |
| T & M Builders Ltd | Construction | 2010 |
| T & P Kitchen Installations Limited | Other services | 2004 |
| T G a Solutions Limited | Wholesale & retail | 2015 |
| T Hall Limited | Manufacturing | 2024 |
| T Howard Group Limited | Administrative & support | 2020 |
| T Oistin's Limited | Hospitality | 2025 |
| T R Last Services Limited | Professional & scientific | 2013 |
| T-A Accounts Ltd | Professional & scientific | 2013 |
| T.A.G. Associates Limited | Professional & scientific | 2014 |
| TA-65 (UK) Limited | Wholesale & retail | 2017 |
| Tactical Cables Limited | Wholesale & retail | 2013 |
| Take IT Away (EN) Ltd | Wholesale & retail | 2017 |
| Tarquin Bilgen Limited | Wholesale & retail | 2014 |
| Tasarla Studios Ltd | Professional & scientific | 2026 |
| Tattoo Tea Party Limited | Arts & recreation | 2011 |
| Tattoos and Blues Limited | Other services | 2021 |
| Tatum's Teahouse Ltd | Hospitality | 2019 |
| Taylor Analytical Spectroscopy Services Limited | Manufacturing | 2017 |
| Taylors Plumbing & Heating Limited | Construction | 1987 |
| TC Signalling Services Ltd | Manufacturing | 2017 |
| TCB Carpentry and General Building Ltd | Construction | 2018 |
| Tckiteuk Ltd | Financial services | 2025 |
| TCM Spraying Services Limited | Wholesale & retail | 2012 |
| TDO Bespoke Builders Limited | Construction | 2021 |
| TDT PUB Company Ltd | Hospitality | 2022 |
| Tea Dunk Games Limited | Information & communication | 2025 |
| Tea Shop Productions Ltd | Information & communication | 2019 |
| Team Bull Limited | Professional & scientific | 2008 |
| Technik Automotive Ltd | Wholesale & retail | 2021 |
| Technology Networks Limited | Information & communication | 2000 |
| Technology Tamed Limited | Information & communication | 1996 |
| TED Engineering Consultants Ltd | Professional & scientific | 2022 |
| Teds Transport Company Ltd | Transport & logistics | 2026 |
| Tekden Limited | Hospitality | 2018 |
| Tempura Limited | Extraterritorial | 1995 |
| Terra Incognita Limited | Construction | 2025 |
| Test Plugs Limited | Manufacturing | 1975 |
| Tgiuk (Togetherintheuk) CIC | Information & communication | 2016 |
| THA Advisory Limited | Professional & scientific | 2026 |
| Thalidomide Voice Ltd | Other services | 2023 |
| Thanet Mortgages Limited | Financial services | 2020 |
| That Media and Design Limited | Information & communication | 2015 |
| THE Acton Crown Inn Ltd | Hospitality | 2024 |
| THE Arches (Heathcote Road Bordon) Management Company Limited | Households | 2008 |
| THE Ballingdon Group Limited | Financial services | 2025 |
| THE Barbershop (King Street) Limited | Other services | 2013 |
| THE Beauty Edit Sudbury Ltd | Other services | 2026 |
| THE Boat House Mews (Clare) Management Company Limited | Real estate | 2005 |
| THE Briars Residential and Care Limited | Health & social care | 2013 |
| THE Brothers COX Limited | Wholesale & retail | 2016 |
| THE Brunswick Art Gallery Ltd | Wholesale & retail | 2022 |
| THE Camera Guysuk Ltd | Information & communication | 2019 |
| THE Christopher Centre | Real estate | 2007 |
| THE Cloisters (Sudbury) Management Limited | Real estate | 2005 |
| THE Cooking OIL Guys Limited | Water & waste | 2012 |
| THE Cottage Agency Ltd | Hospitality | 2003 |
| THE Culture Auditor Limited | Professional & scientific | 2015 |
| THE Curtain Exchange Limited | Wholesale & retail | 1989 |
| THE Eco News Ltd | Information & communication | 2021 |
| THE Equas Partnership 2020 Limited | Professional & scientific | 2016 |
| THE Evacuation Company Ltd | Public administration | 2024 |
| THE Fabmax Company Ltd | Information & communication | 2018 |
| THE Fabric Cellar Ltd | Wholesale & retail | 2026 |
| THE Family and Community Network | Health & social care | 2010 |
| THE Fluidity Group Limited | Arts & recreation | 2026 |
| THE Gepbetto Ltd | Hospitality | 2024 |
| THE Global SWEETS123 Limited | Wholesale & retail | 2024 |