| Ryan Edwards Paving Limited | Administrative & support | 2025 |
| S J Geomatics Ltd | Professional & scientific | 2012 |
| Safecat UK Limited | Manufacturing | 2022 |
| Sarene Creole Cuisine Limited | Hospitality | 2022 |
| Satnav Specialist Ltd | Other services | 2014 |
| Saxon Road Day Care Ltd | Health & social care | 2017 |
| Saxon Wines Limited | Wholesale & retail | 2016 |
| SCC (Lowestoft) Limited | Wholesale & retail | 2022 |
| Scoones Partnership Limited | Agriculture & fishing | 2010 |
| Scott Baxter Plumbing & Heating Limited | Construction | 2003 |
| Seath Instruments (1992) Limited | Manufacturing | 1992 |
| Serenity Saxmundham Limited | Wholesale & retail | 2019 |
| Sevun Ltd | Extraterritorial | 2013 |
| Shapla Curry House Limited | Hospitality | 2026 |
| Sharp Print Limited | Transport & logistics | 2003 |
| Sharprint Limited | Wholesale & retail | 2010 |
| Sharprint Solutions Limited | Wholesale & retail | 2010 |
| Sheridan Sports Medicine Limited | Health & social care | 2010 |
| Sibton Abbey Holdings Limited | Construction | 2025 |
| Sika Fencing Limited | Construction | 2023 |
| Simatt Associates Limited | Professional & scientific | 2003 |
| Simon Leonard Construction Ltd | Construction | 2015 |
| Sj's UK Engineering Ltd | Manufacturing | 2021 |
| Smithsco Ltd | Real estate | 2015 |
| Smithy's Smokehouse Ltd | Hospitality | 2019 |
| Solar Shelters Limited | Construction | 2023 |
| Southdown Sheep Society(The) | Agriculture & fishing | 1892 |
| Southwold Boating Lake and Tearoom Limited | Arts & recreation | 2003 |
| Southwold Rugby Football Club Limited | Arts & recreation | 2009 |
| Southwold Sports Pavilion Limited | Hospitality | 2018 |
| Spectra Packaging Solutions Limited | Manufacturing | 2007 |
| SPM Fire Safety Consultancy Ltd | Financial services | 2017 |
| Staanabell Limited | Professional & scientific | 2018 |
| Stellar Developments Anglia Limited | Construction | 2007 |
| Stephen Bealing Limited | Agriculture & fishing | 2019 |
| Still Southwold Limited | Hospitality | 2017 |
| Stohr Holdings Ltd | Real estate | 2020 |
| Stone & Mist Ltd | Wholesale & retail | 2025 |
| Stone House One Ltd | Agriculture & fishing | 2024 |
| Storm-Furniture Limited | Manufacturing | 2013 |
| Striptees Limited | Professional & scientific | 2015 |
| SUE Blakeley Limited | Administrative & support | 2003 |
| Sueno London Ltd | Professional & scientific | 2019 |
| Suffolk & Norfolk Property Services Ltd | Real estate | 2015 |
| Suffolk Adventures Ltd | Administrative & support | 2020 |
| Suffolk Artlink | Education | 2005 |
| Suffolk Car Centre Limited | Wholesale & retail | 2017 |
| Suffolk Hutmakers Ltd | Construction | 2015 |
| Sunrise at Marty Boys Limited | Hospitality | 2025 |
| Sunrise at Zaks Ltd. | Hospitality | 2005 |
| Superfry (Beccles) Limited | Hospitality | 2011 |
| Superfry Ltd | Hospitality | 2002 |
| Swayprime Development Limited | Construction | 2019 |
| Swayprime Limited | Real estate | 1984 |
| T D R Dressage Limited | Agriculture & fishing | 2020 |
| T&B Paving Ltd | Construction | 2026 |
| Tagr Network Limited | Information & communication | 2019 |
| Tagr Property Services Limited | Real estate | 2018 |
| Tessa Newcomb Limited | Arts & recreation | 2003 |
| THE Beginning Agency Ltd | Other services | 2022 |
| THE Chedley Fold Limited | Agriculture & fishing | 2013 |
| THE Feedbarn (Suffolk) Limited | Wholesale & retail | 2016 |
| THE Green House Suffolk Ltd | Wholesale & retail | 2022 |
| THE Limes Residents Association Limited | Health & social care | 1992 |
| THE Martins Property Management Company (Walberswick) Limited | Households | 2005 |
| THE Morton Partnership Limited | Professional & scientific | 1992 |
| THE Norfolk Hare Ltd | Administrative & support | 2018 |
| THE Oaks Holton Management Company Limited | Households | 2002 |
| THE Old Drill Hall Management Company Limited | Households | 2011 |
| THE Silo Cafe Ltd | Hospitality | 2023 |
| THE Suffolk Company Limited | Real estate | 2024 |
| THE Values Revolution Limited | Extraterritorial | 2024 |
| THE Wissett Plough Ltd | Hospitality | 2026 |
| Thebusylittlepubcompany Limited | Hospitality | 2012 |
| Themediaworks Limited | Information & communication | 2022 |
| Thickitts Farm Shop Ltd | Wholesale & retail | 2015 |
| Thirty Three Thirty Three Ltd | Administrative & support | 2013 |
| Thorpenessfoodcompany Limited | Hospitality | 2007 |
| TIM Sparkes Ltd | Professional & scientific | 2020 |
| TK Golf Ltd | Wholesale & retail | 2022 |
| Tomographer Ltd. | Professional & scientific | 2020 |
| Tops Holdings Limited | Real estate | 2008 |
| Townsend Nuclear Limited | Construction | 2024 |
| Transforming Hope, Raising Impact Values and Empowerment (Thrive) C.I.C. | Other services | 2024 |
| Treviem Ltd | Professional & scientific | 2019 |
| Triple S Solutions Limited | Administrative & support | 2020 |
| Tristanflute Limited | Information & communication | 2016 |
| Trulock and Harris Limited | Wholesale & retail | 1991 |
| Turner & Kent Construction Limited | Construction | 2021 |
| Twiggys Limited | Other services | 2018 |
| UK Land Surveys Ltd | Professional & scientific | 2012 |
| Unit 49 Ltd | Wholesale & retail | 2019 |
| Unitlight Limited | Transport & logistics | 1998 |
| Untested Limited | Wholesale & retail | 1999 |
| UP Country Autoproducts (U.K.) Limited | Wholesale & retail | 1982 |
| Utting Electrical Limited | Manufacturing | 2017 |
| V N P Limited | Information & communication | 2009 |
| Vally Farm Vineyard Limited | Agriculture & fishing | 2020 |
| Van Dijk & SON Limited | Real estate | 2020 |
| Van Dijk Accountants Limited | Professional & scientific | 1987 |