| Sounds East CIC | Arts & recreation | 2021 |
| Soundsteps App Ltd | Information & communication | 2026 |
| South Brook Property Ltd | Construction | 2022 |
| South Coast Serviced Accommodation Ltd | Administrative & support | 2016 |
| South Coast Trucking Ltd | Transport & logistics | 2022 |
| South Rural PCN Ltd | Health & social care | 2022 |
| South Street Pubs Ltd | Hospitality | 2006 |
| South Street Studios Ltd | Real estate | 2020 |
| South Suffolk LOW Carbon Food Community Interest Company | Agriculture & fishing | 2012 |
| South Uttlesford PCN Limited | Health & social care | 2023 |
| South Wales Getaways Limited | Real estate | 2023 |
| Southgate & Culham Limited | Construction | 2005 |
| Southgate Cleaning Solutions Ltd | Administrative & support | 2016 |
| Southgates Bespoke Furniture Ltd | Manufacturing | 2025 |
| Southpoint Project Services Ltd | Professional & scientific | 2026 |
| Southwold Properties Limited | Real estate | 2000 |
| Southwold Road Industrial Park Ltd | Real estate | 2012 |
| Sowhat? Consultancy Ltd | Health & social care | 2022 |
| Soyca Ltd | Real estate | 2021 |
| SP Building & Renovations Limited | Construction | 2025 |
| SP Data Consultancy Ltd | Information & communication | 2016 |
| SP Mace (Suffolk) Ltd | Professional & scientific | 2020 |
| Space for the Wild | Arts & recreation | 2023 |
| Space Invaderz Limited | Administrative & support | 2021 |
| Space Simplified Limited | Extraterritorial | 2014 |
| Space Tunc Company Ltd | Wholesale & retail | 2023 |
| Spacenest Corporation Limited | Wholesale & retail | 2026 |
| Spacy Homes Ltd | Real estate | 2019 |
| Spadag Health Care Ltd | Health & social care | 2024 |
| Sparkhes Limited | Professional & scientific | 2024 |
| Sparkle Clean BNB and Linen Hire Ltd | Administrative & support | 2025 |
| Sparkle Hand Car Wash Ltd | Other services | 2025 |
| Sparred Ltd | Wholesale & retail | 2008 |
| Sparrowe Ltd | Professional & scientific | 2026 |
| Sparta Cleaning Ltd | Administrative & support | 2025 |
| Spartan IT Systems Ltd | Other services | 2020 |
| Spartan Tool Van Ltd | Wholesale & retail | 2026 |
| Spean Property Ltd | Professional & scientific | 2018 |
| Spear Plumbing Ltd | Construction | 2014 |
| Spear Shield Ltd | Professional & scientific | 2021 |
| Special Auto Solutions Limited | Wholesale & retail | 2024 |
| Special Day Events Limited | Hospitality | 2020 |
| Special Kebab Limited | Hospitality | 2019 |
| Special Material Product Limited | Manufacturing | 2026 |
| Specialist Window Cleaning Limited | Administrative & support | 2011 |
| Spectacular Activities Ltd | Health & social care | 2020 |
| Spectranomy Limited | Information & communication | 2019 |
| Speed Style Promotions Ltd | Wholesale & retail | 2012 |
| Spencer Asset Holdings Limited | Real estate | 2026 |
| Spencer Bird Limited | Administrative & support | 2002 |
| Spending Limited | Hospitality | 2026 |
| Spes Bona ET Fortuna Limited | Administrative & support | 2024 |
| Spettigue Property Development Co Limited(The) | Construction | 1963 |
| Spevell Limited | Construction | 1976 |
| Spevivit Ltd | Professional & scientific | 2023 |
| SPF Property Limited | Real estate | 2025 |
| Spice Diner Ltd | Hospitality | 2022 |
| Spice of India Gate Ltd | Hospitality | 2022 |
| Spider Network Subsidiaries Ltd | Real estate | 2016 |
| Spider Networks Ltd | Information & communication | 2015 |
| Spider Recruitment Services Limited | Administrative & support | 2015 |
| Spider Web Recruitment Ltd | Administrative & support | 2013 |
| Spidon Limited | Information & communication | 2003 |
| Spill Festival Ltd | Arts & recreation | 1999 |
| Spill the Chai Ltd | Wholesale & retail | 2026 |
| Spillers Pantomimes Limited | Arts & recreation | 1997 |
| Spinal Expert Witness Limited | Administrative & support | 2022 |
| Spindle House (Management Company) Limited | Households | 2020 |
| Spinnaker Capital Management Limited | Real estate | 2014 |
| Spinners Transport Ltd | Transport & logistics | 2016 |
| Spiral Appointments Limited | Administrative & support | 2012 |
| Spire Logic Ltd | Construction | 2026 |
| Spirit & Skin Ltd | Health & social care | 2021 |
| Spirit Yachts Holdings Limited | Manufacturing | 2023 |
| Spiritual Gardens Limited | Administrative & support | 2022 |
| Spitalfields Works Limited | Construction | 2016 |
| Spitalfields Works Residential Limited | Real estate | 2022 |
| Splendid Housing Limited | Health & social care | 2018 |
| Splendid Torch Ltd | Wholesale & retail | 2026 |
| Sponsus Organisation Ltd | Information & communication | 2019 |
| Spoon Ipswich Ltd | Hospitality | 2016 |
| Sport Dawg Ltd | Arts & recreation | 2024 |
| Sport First Ventures Ltd | Administrative & support | 2024 |
| Sport Sense Ltd | Education | 2024 |
| Sporting Futures Group Ltd | Professional & scientific | 2020 |
| Sporting Halo Limited | Extraterritorial | 2019 |
| Sports Investments (UK) Ltd | Wholesale & retail | 2014 |
| Sportsmed East Limited | Arts & recreation | 2002 |
| Sportsmed Physio Limited | Arts & recreation | 2008 |
| Spot Market Ltd | Information & communication | 2017 |
| Spotless Surroundings Limited | Other services | 2018 |
| Spotwellbeing CIC | Health & social care | 2019 |
| Spranto Ltd | Real estate | 2020 |
| Spray Property Limited | Real estate | 2020 |
| Spring Gate VS Ltd | Other services | 2020 |
| Spring Road Limited | Real estate | 2008 |
| Spring Tyre Service Ltd | Wholesale & retail | 2020 |
| Springbok Apartments Ltd | Real estate | 2019 |
| Springbok House (Freehold) Company Limited | Households | 2006 |
| Springs Convenience Ltd | Wholesale & retail | 2022 |