| Starr Performance Limited | Professional & scientific | 2008 |
| Start Mediation Ltd | Other services | 2016 |
| STARTRUCKS777 Ltd | Wholesale & retail | 2022 |
| STAT-24 Ltd | Health & social care | 2014 |
| Statbooks Ltd | Information & communication | 2013 |
| Statbooks Online Limited | Information & communication | 2013 |
| Statera Group Ltd | Professional & scientific | 2019 |
| Static Caravans Direct Limited | Wholesale & retail | 2010 |
| Staticsure Living Solutions Limited | Wholesale & retail | 2026 |
| Station Styles Grooming Ltd | Other services | 2022 |
| Statscope Ltd | Information & communication | 2026 |
| Status 11 Consulting Limited | Public administration | 2018 |
| Status Office Services Ltd. | Wholesale & retail | 1998 |
| Stay With US MPB Ltd | Real estate | 2023 |
| STB Services Limited | Other services | 2020 |
| STC Solutions Ltd | Wholesale & retail | 2001 |
| STE UK Group Ltd | Information & communication | 2018 |
| Steadfast Housing Ltd | Households | 2026 |
| STEADY5 Limited | Wholesale & retail | 2025 |
| Stealth Electronics Limited | Manufacturing | 2000 |
| Steamboat Tavern Ltd | Hospitality | 2014 |
| Stedman's Estates Limited | Households | 2018 |
| Steeple Professional Services Ltd | Professional & scientific | 2012 |
| Stefan Cleaning Ltd Ltd | Administrative & support | 2025 |
| Steggalls Ltd | Construction | 2025 |
| Stella Services Ltd | Health & social care | 2025 |
| Stellar PAT Limited | Administrative & support | 2022 |
| Stellarhaul Solutions Ltd | Extraterritorial | 2026 |
| Stellarsocial Ltd | Construction | 2022 |
| Stelmax Limited | Manufacturing | 1960 |
| Stephen Burton Darts Limited | Arts & recreation | 2019 |
| Stephen John Limited | Other services | 2008 |
| Steponix Ltd | Professional & scientific | 2026 |
| Stepover Coaching Ltd | Education | 2025 |
| Sterling CPA Ltd | Professional & scientific | 2025 |
| Sterling State Holdings Ltd | Financial services | 2021 |
| Sterling State Lettings Ltd | Real estate | 2021 |
| Sterlington Injectable Pharmaceutical UK Ltd | Wholesale & retail | 2026 |
| Steve Albins Carpentry (2012) Ltd | Construction | 2012 |
| Steve Allman Limited | Professional & scientific | 2012 |
| Steve Leggett Limited | Construction | 2003 |
| Steve Lock Limited | Manufacturing | 2002 |
| Steve Smith Electrical Contractors Ltd | Construction | 2015 |
| Steve V Armes Ltd | Manufacturing | 2010 |
| Steve White Industrial Roofing Limited | Construction | 2005 |
| Steven Abbott Tcnf Limited | Professional & scientific | 2009 |
| Steven Dewberry Opticians Limited | Wholesale & retail | 2002 |
| Steven R Potkins Limited | Construction | 2003 |
| Stevenson Carpentry Ltd. | Construction | 2003 |
| Stevenson Estates Limited | Real estate | 2012 |
| Stevenson Road (Ipswich) Maintenance Company Limited | Households | 1999 |
| Steward Farming Limited | Agriculture & fishing | 2026 |
| Stewart Beamont Associates Ltd | Professional & scientific | 2005 |
| Stewart Wealth Management Ltd | Financial services | 2008 |
| Stilton Advertising Limited | Professional & scientific | 1995 |
| Sting Accountants Ltd | Professional & scientific | 2021 |
| Stirling Limited | Professional & scientific | 2004 |
| STJ Castro Limited | Wholesale & retail | 2025 |
| Stock Medical Limited | Wholesale & retail | 2009 |
| Stockbull UK Ltd | Wholesale & retail | 2024 |
| Stockwood Domestic Builder Ltd | Construction | 2021 |
| Stoev Ltd | Transport & logistics | 2021 |
| STOEV2000 Ltd | Transport & logistics | 2024 |
| Stoiana Transport Ltd | Transport & logistics | 2019 |
| Stoke Bridge Maltings Residents' Association Limited | Households | 1985 |
| Stoke-On-Trent City Centre BID Limited | Administrative & support | 2017 |
| Stoked Ipswich CIC | Arts & recreation | 2023 |
| Stokes and Cahill Group Limited | Financial services | 2026 |
| Stokes Electrical Limited | Construction | 2024 |
| Stone Business Transformations Limited | Professional & scientific | 2025 |
| Stone Dead Media Group Ltd | Extraterritorial | 2022 |
| Stone Lane Developments Limited | Construction | 2022 |
| Stone Lodge (Ipswich) Management Company Limited | Households | 2003 |
| Stone Street Court Management Company Limited | Administrative & support | 2006 |
| Stoneleigh Kingsland Limited | Hospitality | 2023 |
| Stonelodge Homes Limited | Real estate | 2022 |
| Stones & Steel Development Ltd | Construction | 2025 |
| Stones Auto Repairs Ltd | Wholesale & retail | 2026 |
| Stonewood Gate Investment Ltd | Real estate | 2020 |
| Stonewood Gate Ltd | Construction | 2019 |
| Stop IT Limited | Professional & scientific | 2011 |
| Stop Noodle Ltd | Hospitality | 2024 |
| Stop&Shop Ipswich Ltd | Wholesale & retail | 2022 |
| Store Secure Ltd | Professional & scientific | 2025 |
| Storico Ltd | Hospitality | 2024 |
| Storman Software Ltd | Information & communication | 2008 |
| Storrberry Ltd | Wholesale & retail | 2024 |
| Storrer and Co Accountants Limited | Professional & scientific | 2023 |
| Storycase Limited | Information & communication | 1993 |
| Stour Advisory Ltd | Professional & scientific | 2026 |
| Stour Ecology Ltd | Professional & scientific | 2025 |
| Stour Edge Limited | Administrative & support | 2022 |
| Stour Engineering LLP | | 2011 |
| Stour FEN Developments Limited | Construction | 2020 |
| Stour Valley Catering Limited | Hospitality | 2019 |
| Stour Valley Holdings Limited | Financial services | 2020 |
| Stourside Farming Limited | Agriculture & fishing | 2011 |
| Stout Bavarian Limited | Administrative & support | 2014 |
| Stowbox Ltd | Transport & logistics | 2005 |
| Stowmarket and District Motor Cycle Club Limited | Arts & recreation | 1985 |