| S Page Fishmonger Limited | Wholesale & retail | 2006 |
| S W Dewell Building Contractors Ltd | Construction | 2015 |
| S White Marine Ltd | Transport & logistics | 2022 |
| S&C Parker Limited | Real estate | 2019 |
| S&J Lifestyle and Medical Ltd | Health & social care | 2025 |
| S&R Hospitality Ltd | Hospitality | 2025 |
| S&S Sound and Lighting Hire Limited | Administrative & support | 2016 |
| S.D Account Ltd | Professional & scientific | 2021 |
| S.G.S. Inspection Limited | Other services | 2022 |
| S.Scarff Ltd | Construction | 2022 |
| S@@F Ltd | Agriculture & fishing | 2020 |
| S@@F Properties Ltd | Real estate | 2021 |
| Sabby TCG Limited | Wholesale & retail | 2025 |
| Safety and Marine Solutions Limited | Professional & scientific | 2015 |
| Safety Boat Solutions Ltd | Construction | 2024 |
| Safeworx Limited | Professional & scientific | 2010 |
| Saffa Spaza Limited | Manufacturing | 2025 |
| Sagem Properties Ltd | Real estate | 2020 |
| Saham Asset Management Ltd | Real estate | 2023 |
| Salt and Sails Ltd | Real estate | 2025 |
| Saltwater Chalet Ltd | Hospitality | 2016 |
| SAM Cole Food Limited | Wholesale & retail | 1999 |
| SAM Cole Food Service Limited | Hospitality | 2021 |
| SAM Cole Properties Limited | Real estate | 2012 |
| SAM DOY Carpentry and Construction Limited | Construction | 2026 |
| Same Day Tool Hire Ltd | Administrative & support | 2025 |
| Sams Cafe Community Hub CIC | Health & social care | 2026 |
| Sancroft Square (Harleston) Management Company Limited | Households | 2007 |
| Sandy Toes Lowestoft Limited | Hospitality | 2016 |
| Sannick Ltd | Other services | 2021 |
| Sansar Parenting Limited | Health & social care | 2006 |
| Sapphire Building Service Ltd | Construction | 2025 |
| Sara Norfolk Limited | Mining & quarrying | 2017 |
| SAS Tool Hire & Sales Ltd | Manufacturing | 2019 |
| Satel Electronics Limited | Manufacturing | 2003 |
| Sayers Transport Limited | Wholesale & retail | 2019 |
| SB Properties (East Anglia) Limited | Real estate | 2022 |
| SBS Assets Limited | Real estate | 2023 |
| SCA Property Rentals Limited | Real estate | 2023 |
| Scarlett's Logistics Ltd | Transport & logistics | 2019 |
| Scenic Pantomimes Limited | Manufacturing | 2005 |
| Scenic Projects (Holdings) Limited | Manufacturing | 2005 |
| Scenic Projects Limited | Arts & recreation | 1996 |
| Scenic Transportation Services Limited | Transport & logistics | 2011 |
| Schroder Mechanical Services Limited | Construction | 2025 |
| Scope 2 Maintenance Solutions Limited | Other services | 2024 |
| SCOPE2 Property Services Ltd | Real estate | 2024 |
| Scott Goodings Builders Limited | Construction | 2008 |
| Screens Embroidery & Printing Limited | Wholesale & retail | 2018 |
| Scrivens Construction Limited | Construction | 2024 |
| SD Property Renovations Ltd | Construction | 2023 |
| SDB1 Limited | Wholesale & retail | 2026 |
| SE Spurgeon Limited | Construction | 2008 |
| Sea Scaffolding Limited | Construction | 2009 |
| Seam Limited | Construction | 2001 |
| Seamoht Limited | Professional & scientific | 2024 |
| Seascape Properties (Lowestoft) Limited | Real estate | 1958 |
| Seatrium Offshore Renewable Services Ltd | Manufacturing | 2010 |
| Seconds Catering Ltd | Hospitality | 2024 |
| Sefftons Estate Agents Limited | Real estate | 2023 |
| Sefftons Ltd | Real estate | 2020 |
| Seismic Technology Limited | Information & communication | 1996 |
| Select Credit Management Ltd | Administrative & support | 2010 |
| SEM- Cetom Limited | Health & social care | 2023 |
| Sendmart Ltd | Wholesale & retail | 2015 |
| Senior Authorised Person Services Ltd | Information & communication | 2018 |
| Senses Holiday Limited | Administrative & support | 2004 |
| Senyl BE Ltd | Administrative & support | 2024 |
| Sequentis Enterprises Ltd | Education | 2022 |
| Serendib Property UK Holdings (DS) Limited | Construction | 2019 |
| Serendip Holdco Limited | Financial services | 2016 |
| Serendip Midco Limited | Financial services | 2016 |
| Serendip Property Holdings Limited | Real estate | 2019 |
| Serenity Beach Ltd | Hospitality | 2022 |
| Sesss Limited | Wholesale & retail | 2007 |
| Seven Stars Property Management Limited | Real estate | 2022 |
| SG Engineering (East Anglia) Ltd | Construction | 2024 |
| SGB Electrical (East Anglia) Limited | Construction | 2009 |
| SGL Logistics Limited | Transport & logistics | 2009 |
| Shadow Aspects Ltd | Arts & recreation | 2021 |
| Shambles Limited | Manufacturing | 2003 |
| Shandwick Properties (Lowestoft) Limited | Real estate | 1971 |
| Shannon Beare Conveyancing Limited | Professional & scientific | 2025 |
| Sharda Rose Limited | Information & communication | 2017 |
| Sharebetter Limited | Real estate | 1990 |
| Shari Dreamz Ltd | Wholesale & retail | 2025 |
| Sharman Hydraulics Ltd | Other services | 2023 |
| Sharp Contract & Surveying Ltd | Professional & scientific | 2009 |
| Sharp Contract Experts and Training Ltd | Construction | 2026 |
| Sharp Property (Lets) Ltd | Real estate | 2019 |
| Sharpes Couriers Ltd | Transport & logistics | 2025 |
| Shazlee Properties Ltd | Real estate | 2020 |
| SHE Does Safety Ltd | Professional & scientific | 2022 |
| Sheffs 247 Ltd | Arts & recreation | 2021 |
| Shepherds NDT Ltd | Construction | 2023 |
| Sherlock Cones Ltd | Administrative & support | 2018 |
| Sherou’S Ltd | Hospitality | 2024 |
| Shibapharm Ltd | Professional & scientific | 2026 |
| Shillbrook Homes Limited | Real estate | 2022 |
| Shish Anatolia Ltd | Hospitality | 2022 |