| Steve Flatt Plumbing & Heating Ltd | Construction | 2011 |
| Steve Sturman Welding Services Limited | Manufacturing | 2016 |
| Steve's Seadish Limited | Wholesale & retail | 2023 |
| Steven Allen Welding Services Limited | Construction | 2018 |
| Stewart Howard (Holdings) Limited | Financial services | 2020 |
| Stitch Creative Agency Ltd | Information & communication | 2023 |
| STM Leisure Limited | Arts & recreation | 2004 |
| Stoneshore Management Limited | Professional & scientific | 2022 |
| Store IT Right (EA) Ltd | Transport & logistics | 2010 |
| Stradbroke House Management Company Limited | Real estate | 2003 |
| Strowlger Investments Limited | Administrative & support | 2008 |
| Structured Information Technology Solutions Ltd | Information & communication | 2003 |
| STS 25 Ltd | Water & waste | 2026 |
| Stuart Buskell Limited | Professional & scientific | 2013 |
| Stuart Chase Financial Planning Ltd | Professional & scientific | 2018 |
| Studio More Design Ltd. | Manufacturing | 2015 |
| Sturco Limited | Energy | 2017 |
| Subsea Charting Services Limited | Professional & scientific | 2026 |
| Subsea Connector Consultancy Ltd | Professional & scientific | 2023 |
| Subsonic Sound Systems Ltd | Manufacturing | 2025 |
| Suffolk Boat Services Ltd | Manufacturing | 2023 |
| Suffolk Broads Leisure Ltd | Real estate | 2023 |
| Suffolk Civil & Marine Ltd | Construction | 2020 |
| Suffolk Coastal Escapes Limited | Hospitality | 2025 |
| Suffolk Home Co Buying Ltd | Real estate | 2020 |
| Suffolk Maintenance Limited | Wholesale & retail | 2015 |
| Suffolk Marine Limited | Other services | 2013 |
| Suffolk Risk & Compliance Limited | Professional & scientific | 2025 |
| Suffolk Stoves Limited | Wholesale & retail | 2014 |
| Suffolk Trade Frames Ltd | Construction | 2022 |
| Suffolk Wood Veneers Limited | Transport & logistics | 2016 |
| Suker Fabrication Services Limited | Construction | 2015 |
| Summit Safety and Engineering Limited | Manufacturing | 2025 |
| Sun & Soul Cyprus Limited | Administrative & support | 2016 |
| Sun INK Limited | Wholesale & retail | 2008 |
| Sun Kylin (UK) Cultural and Tourism Real Estate Development Co Ltd | Real estate | 2021 |
| Sunbeams Educare Limited | Education | 2011 |
| Sunjunkies Ltd | Wholesale & retail | 2025 |
| Sunjunky's Limited | Other services | 2001 |
| Sunnyside Residents Limited | Professional & scientific | 1994 |
| Sunrise Building Services Limited | Construction | 2026 |
| Sunrise Film Festival CIC | Information & communication | 2026 |
| Sunrise Installations Holdings Limited | Financial services | 2026 |
| Sunway House Limited | Real estate | 1998 |
| Supersine Holdings Group EBT Limited | Professional & scientific | 2009 |
| Supersine Holdings Group Limited | Extraterritorial | 2009 |
| Supportive Education Ltd | Professional & scientific | 2025 |
| Surlingham Garage Limited | Wholesale & retail | 2024 |
| Sustainer Living Ltd | Construction | 2021 |
| SVW Builders Limited | Construction | 2010 |
| SW Procurement Limited | Professional & scientific | 2021 |
| SWA Carpentry Limited | Construction | 2020 |
| Swami Design Ltd | Professional & scientific | 2026 |
| Swap Shop Suffolk C.I.C. | Wholesale & retail | 2026 |
| Swatman Limited | Construction | 2018 |
| Sweet Stagers Ltd | Construction | 2024 |
| Sweet Stays MGT Ltd | Real estate | 2023 |
| Swiftcat Limited | Manufacturing | 2021 |
| Sydenham House Medical Services Ltd | Health & social care | 2005 |
| SZM Marine Services Ltd | Transport & logistics | 2025 |
| T & T Sunshine Properties Ltd | Real estate | 2021 |
| T I Inspiration Limited | Real estate | 2025 |
| T J Fisher Consultancy Limited | Mining & quarrying | 2024 |
| T M Kilbourn Accountancy Ltd | Professional & scientific | 2019 |
| T S F Properties Limited | Real estate | 2022 |
| T S F Sales Training Limited | Administrative & support | 2022 |
| T&T Metal Trading Limited | Wholesale & retail | 2019 |
| T. & J. Commercial Repairs (Anglia) Limited | Wholesale & retail | 1976 |
| TAG Investment Holdings Limited | Real estate | 2025 |
| Take Note Music Company (Lowestoft) Limited | Wholesale & retail | 2012 |
| Taking Back Territory Ltd | Hospitality | 2025 |
| Talha Taxi Limited | Transport & logistics | 2024 |
| Tanya Paxton Coaching Limited | Other services | 2023 |
| Target Trees Limited | Administrative & support | 2021 |
| Tarrants Property Services Limited | Real estate | 2003 |
| Taylor and Tennick Investments Ltd | Hospitality | 2023 |
| Taylor Brothers Lowestoft Ltd | Real estate | 2009 |
| Taylor Marine Service's Limited | Professional & scientific | 2024 |
| Taylor Properties Lowestoft Limited | Real estate | 2021 |
| Taylor Properties Trading Ltd | Construction | 1951 |
| Taylor's RUM LOT Ltd | Wholesale & retail | 2020 |
| Taylor's Yard Management Company Limited | Other services | 2006 |
| Taylormade Design Limited | Arts & recreation | 2009 |
| TB Services (EA) Ltd | Construction | 2026 |
| TB Surveys Ltd | Professional & scientific | 2021 |
| TDP Group Ltd | Construction | 2014 |
| Team 2GETHER CIC | Arts & recreation | 2017 |
| Team Subsea Limited | Professional & scientific | 2023 |
| Team Waveney Swimming Club Limited | Arts & recreation | 2019 |
| Technicruit Limited | Other services | 2023 |
| Technicus Consulting Ltd | Professional & scientific | 2010 |
| Techno Tech Norwich Ltd | Wholesale & retail | 2020 |
| Techplus Limited | Administrative & support | 2016 |
| Techplus Properties Limited | Real estate | 2024 |
| Tecon Grenergy Limited | Professional & scientific | 2021 |
| Teklog Limited | Administrative & support | 2004 |
| Telford 247 Limited | Arts & recreation | 2021 |
| Tell ME on a Tuesday Limited | Professional & scientific | 2016 |
| Temperance Place Management Company Limited | Real estate | 1992 |
| Tempest Properties (Lowestoft) Limited | Real estate | 2021 |