| Slavg Carpentery Limited | Construction | 2025 |
| Slavin Transport Ltd | Transport & logistics | 2019 |
| Slavinjector Repair Service Ltd | Wholesale & retail | 2024 |
| Slcs Properties Ltd | Construction | 2026 |
| Sldonaldson Property Ltd | Real estate | 2020 |
| Slipstream Cricket Limited | Extraterritorial | 2007 |
| SMA Construction Ltd | Other services | 2017 |
| Smart Choice Property Maintenance Ltd | Construction | 2022 |
| Smart Engineering (East Anglia) Limited | Manufacturing | 2009 |
| Smart Roofcare Ltd | Construction | 2024 |
| Smart Wheelchairs Limited | Extraterritorial | 2011 |
| Smartlift Bulk Packaging Ltd. | Administrative & support | 2007 |
| SMC Car Company Ltd | Wholesale & retail | 2020 |
| SME Auto Services Ltd | Wholesale & retail | 2025 |
| SME Auto's Ltd | Wholesale & retail | 2024 |
| SME Business Consultancy and Treasurer Services Limited | Hospitality | 2014 |
| Smith & Williamson Developments Limited | Construction | 2022 |
| Smith Building Services Holdings Limited | Financial services | 2026 |
| Smith Building Services Limited | Construction | 1999 |
| Smith Fine Art Printing Ltd | Manufacturing | 2015 |
| Smith Health Consultancy Limited | Professional & scientific | 2026 |
| Smithee & SON Limited | Wholesale & retail | 2008 |
| Smiths the Bakers (Kings Lynn) Limited | Wholesale & retail | 2003 |
| Smiths the Bakers Ltd | Manufacturing | 2020 |
| SMR Building Contractors Ltd | Construction | 2024 |
| Snam Limited | Real estate | 2020 |
| Snap-On Equipment Limited | Wholesale & retail | 2001 |
| Snowmountain Holdings Limited | Financial services | 2020 |
| Snowmountain International Limited | Financial services | 2020 |
| Snuk Ltd | Administrative & support | 2024 |
| Soares &Source Property Ltd | Real estate | 2022 |
| Socius Dining Ltd | Hospitality | 2016 |
| Sofa Easy Ltd | Wholesale & retail | 2025 |
| Sofia Property Letting Ltd | Hospitality | 2019 |
| Sofianexus Ltd | Information & communication | 2026 |
| Software Alchemy Limited | Information & communication | 2012 |
| Soil Fertility Services Limited | Manufacturing | 2003 |
| Sokol Transport Ltd | Transport & logistics | 2025 |
| Solar Scaffolding Limited | Construction | 2000 |
| Solaris Tanning Studio (Kings Lynn) Ltd | Other services | 2017 |
| Solidex Ltd | Construction | 2024 |
| Solotransa GB Ltd | Transport & logistics | 2016 |
| Solutions on Site (East Anglia) Limited | Information & communication | 2004 |
| Solvita Photography Studios Limited | Professional & scientific | 2023 |
| Somerset Turner Limited | Hospitality | 2017 |
| Sommerfeld & Thomas ( Kings Lynn) Limited | Real estate | 1907 |
| Sonia's Cafe Ltd | Hospitality | 2026 |
| Sorenya Ltd | Professional & scientific | 2020 |
| Sorority Strength Ltd | Arts & recreation | 2023 |
| Soul Kitchen Norfolk Limited | Manufacturing | 2022 |
| South Creake Business Park Limited | Construction | 2020 |
| South POT Ltd | Hospitality | 2025 |
| South Quay Hotels Limited | Hospitality | 2018 |
| South Wootton Foods Ltd | Hospitality | 2023 |
| Southgate Global Finance Limited | Financial services | 2021 |
| Southgate Global Group Limited | Financial services | 2021 |
| Southgate Global Holdings Limited | Financial services | 2021 |
| Southgate Global Limited | Wholesale & retail | 2006 |
| Southmoor Developments LLP | | 2025 |
| Southwold Energy Limited | Administrative & support | 2016 |
| Sowerbys Estate Agents Limited | Real estate | 2006 |
| Sowerbys Holiday Cottages Limited | Hospitality | 2010 |
| Sowerbys Limited | Real estate | 2001 |
| SP Improvements Limited | Professional & scientific | 2012 |
| Spaicit Limited | Real estate | 2022 |
| Spalding & District Wildfowlers Association Limited | Arts & recreation | 2002 |
| SPC (KL) Limited | Professional & scientific | 2020 |
| SPC Properties (EA) Limited | Real estate | 2019 |
| Speak Network | Other services | 2000 |
| Spectacular (EA) Limited | Wholesale & retail | 2009 |
| Spectrum Specialist Consultancy Limited | Health & social care | 2008 |
| Speeds (Nottingham) Limited | Real estate | 2014 |
| Speeds Haggas Limited | Real estate | 2023 |
| Speedway Pro Limited | Wholesale & retail | 2008 |
| Speedway Service Limited | Wholesale & retail | 2003 |
| Spice Garden Restaurant and Takeaway Ltd | Hospitality | 2024 |
| Spice Hill Management Company Ltd | Households | 2018 |
| Spice Inn Restaurant & Takeaway Ltd | Hospitality | 2026 |
| Spice Market Ltd | Wholesale & retail | 2013 |
| Spice Norfolk Limited | Hospitality | 2024 |
| Spider UK Group Limited | Professional & scientific | 2023 |
| Spin and in Ltd | Information & communication | 2026 |
| Spirit Projects Limited | Construction | 2007 |
| SPJ Interiors Limited | Wholesale & retail | 2005 |
| Splendid Reality Ltd | Real estate | 2024 |
| Spontaneous Ltd | Hospitality | 2020 |
| Sporting Knights Limited | Arts & recreation | 2025 |
| Spot Property Management Ltd | Real estate | 2025 |
| Sprayline (UK) Limited | Wholesale & retail | 2012 |
| Springbok Agri Ltd | Manufacturing | 2026 |
| Sprintwave Ltd | Information & communication | 2024 |
| Spunmed Consulting Limited | Professional & scientific | 2020 |
| Squid INK Creative Ltd | Manufacturing | 2023 |
| SR CAD Services Limited | Professional & scientific | 2014 |
| Srbd Southgate Limited | Construction | 2025 |
| SRC Norfolk Ltd | Construction | 2023 |
| SRG Training Limited | Professional & scientific | 2010 |
| Srijeya Properties Ltd | Real estate | 2026 |
| SRN Medical Devices Ltd | Manufacturing | 2021 |
| Srusan Limited | Health & social care | 2017 |