| Stryk Boxing Ltd | Manufacturing | 2025 |
| Stuart Allan Ltd | Professional & scientific | 2020 |
| Stuart Harle Consulting Limited | Information & communication | 2015 |
| Stuart Harris Limited | Extraterritorial | 2014 |
| Stuart House Consulting Ltd | Administrative & support | 2015 |
| Stuart Young Carpentry and Joinery Ltd | Construction | 2022 |
| Studd UK Ltd | Financial services | 2023 |
| Student Rentals Limited | Real estate | 2004 |
| Studently Ltd | Information & communication | 2025 |
| Studio Hedg Architects Ltd | Professional & scientific | 2022 |
| Studio House Properties Ltd | Administrative & support | 2021 |
| Studio Jukes Ltd | Professional & scientific | 2024 |
| Studio Legale AVV Giuseppina Iaria & Associati Limited | Information & communication | 2023 |
| Studio Logoholik Ltd | Professional & scientific | 2024 |
| Studio Matt Canham Limited | Professional & scientific | 2019 |
| Studio Payne Ltd | Professional & scientific | 2023 |
| Studio Rylan Ltd | Arts & recreation | 2023 |
| Studio SIX Aesthetics Ltd | Other services | 2024 |
| Studio Sixty London Limited | Professional & scientific | 2015 |
| Studio to BE Ltd | Professional & scientific | 2022 |
| Studio Withrow Limited | Professional & scientific | 2020 |
| Study in Colchester Limited | Education | 2016 |
| Stuff & Nonsense Props Limited | Other services | 2022 |
| Stunam UN Limited | Extraterritorial | 2024 |
| Stva Developments Ltd | Construction | 2026 |
| Style Design (UK) Limited | Wholesale & retail | 2006 |
| Stylish Veil Boutique Limited | Wholesale & retail | 2025 |
| Stylogy Limited | Other services | 2023 |
| Styne Greenhouses Ltd | Construction | 2022 |
| Styne Properties Limited | Real estate | 2025 |
| STZ Enterprise Ltd | Real estate | 2024 |
| STZ Limited | Construction | 2023 |
| SU Homes Limited | Extraterritorial | 2018 |
| Suarez Limited | Arts & recreation | 2024 |
| SUB & Save Limited | Wholesale & retail | 2025 |
| Subgero Ltd | Administrative & support | 2017 |
| Subtle Interiors Ltd | Construction | 2013 |
| Success Recruit Ltd | Administrative & support | 2012 |
| Successbeauty Hair and Accessories Limited | Other services | 2026 |
| Successful Journey Ltd | Health & social care | 2022 |
| Succession Sport Ltd | Professional & scientific | 2019 |
| Succulents World Limited | Wholesale & retail | 2022 |
| Sudbury Curtain Contracts Limited | Manufacturing | 2001 |
| Sudbury Escape Rooms Ltd | Arts & recreation | 2021 |
| Sudbury Motorcycle Club Limited | Arts & recreation | 1992 |
| Sudbury Sushi Ltd | Hospitality | 2023 |
| Sudhana Properties Limited | Real estate | 1996 |
| Sudhana UK Properties Ltd | Real estate | 2025 |
| SUE Ryder | Health & social care | 1968 |
| SUE Ryder Direct Limited | Wholesale & retail | 1966 |
| SUE Ryder Lottery Limited | Arts & recreation | 2015 |
| Sue's Gardening Service Ltd | Administrative & support | 2017 |
| Suffolk Construction Partners Limited | Construction | 2013 |
| Suffolk Dent Repair Limited | Wholesale & retail | 2025 |
| Suffolk Developments (IOW) Limited | Professional & scientific | 1997 |
| Suffolk Groundworks Ltd | Construction | 2019 |
| Suffolk Helicopters Limited | Transport & logistics | 2005 |
| Suffolk Holdings Limited | Real estate | 1997 |
| Suffolk Leisure Ltd | Wholesale & retail | 2025 |
| Suffolk Mechanical Services Ltd | Construction | 2026 |
| Suffolk Pads Limited | Households | 2013 |
| Suffolk Rentals Limited | Real estate | 2023 |
| Sugar Lens Productions Limited | Extraterritorial | 2011 |
| Sugrins Ltd | Manufacturing | 2021 |
| SUI Generis Holdings Limited | Professional & scientific | 2003 |
| SUI Generis International Limited | Construction | 2000 |
| Sull Prop Ltd | Real estate | 2020 |
| Sullivans Fish Limited | Hospitality | 2019 |
| Sumac Consulting Ltd | Professional & scientific | 2022 |
| Sumac Group Ltd | Financial services | 2022 |
| Sumac London Ltd | Wholesale & retail | 2021 |
| Sumaqui Limited | Wholesale & retail | 1996 |
| Sumedh Household Supplies Limited | Wholesale & retail | 2026 |
| Sumit Financial Limited | Households | 2007 |
| Summerfield Medical Limited | Health & social care | 2003 |
| Summerfield Stud Ltd | Agriculture & fishing | 2024 |
| Summit Construct Ltd | Construction | 2024 |
| Summit Mortgages Ltd | Financial services | 2023 |
| Summit Power Solutions Ltd | Construction | 2025 |
| Sun Lion Properties Limited | Real estate | 2006 |
| Sun Play Therapy Limited | Education | 2026 |
| Sun Point Limited | Other services | 2020 |
| Sun Rays Energy Limited | Information & communication | 2013 |
| Sun-Cell Renewables Limited | Construction | 2024 |
| Sunbird Wines UK Ltd | Wholesale & retail | 2012 |
| Sunbursting Design Services Ltd | Information & communication | 2024 |
| Sunbury Homes Limited | Construction | 2011 |
| Sunelectrical Ltd | Construction | 2021 |
| Sunergys Consulting Limited | Manufacturing | 2025 |
| Sunflower Sensory CIC | Health & social care | 2025 |
| Sunita Candeias Ltd | Health & social care | 2025 |
| Sunlight Healthcare Ltd | Health & social care | 2015 |
| Sunntrac Ltd | Wholesale & retail | 2024 |
| Sunnucks Farms Limited | Agriculture & fishing | 2012 |
| Sunny Beach Holidays Ltd | Hospitality | 2020 |
| Sunny Nine Ltd | Hospitality | 2021 |
| Sunny Superfoods Ltd | Information & communication | 2012 |
| Sunnydp Ltd | Hospitality | 2018 |
| Super Cheap 3D Ltd | Professional & scientific | 2016 |
| Super County Ltd | Arts & recreation | 1998 |