| Sportsmed Products Limited | Administrative & support | 2015 |
| Spot Go Cleaners Limited | Administrative & support | 2025 |
| Spotted Point Ltd | Wholesale & retail | 2023 |
| Spqg Investments Limited | Professional & scientific | 2013 |
| Spring Tide Partnership Ltd | Information & communication | 2022 |
| Springfield Farming Limited | Agriculture & fishing | 1987 |
| Springfielder Limited | Administrative & support | 2022 |
| Springleaf Ltd | Administrative & support | 2019 |
| Sprinter Express Ltd | Transport & logistics | 2006 |
| Sprinthand Limited | Wholesale & retail | 1983 |
| Spriya Technologies Ltd | Information & communication | 2015 |
| Sprout Business Partners Ltd | Extraterritorial | 2024 |
| Spudsaway Aylesbury Ltd | Hospitality | 2025 |
| Spudsaway Ltd | Hospitality | 2026 |
| SPW Transport Ltd | Transport & logistics | 2026 |
| Squadron Pharmaceuticals Limited | Wholesale & retail | 2025 |
| Squadron Technical Services Limited | Information & communication | 2017 |
| Square Glaze Ltd | Construction | 2021 |
| Square Tree Print Limited | Manufacturing | 2011 |
| Squareblue Solutions Limited | Information & communication | 2012 |
| Squeegeeclean Ltd | Administrative & support | 2026 |
| SR Infotech Limited | Information & communication | 2023 |
| SRA UK Properties Limited | Real estate | 2024 |
| SRB Building & Construction Limited | Construction | 2019 |
| Sree Accountants Ltd | Professional & scientific | 2016 |
| Sree Financial Services Ltd | Financial services | 2024 |
| Srff Ltd | Hospitality | 2020 |
| SRI Adoram Ltd | Professional & scientific | 2021 |
| SRI IT Consultancy Ltd | Information & communication | 2019 |
| SRI JAM Ltd | Wholesale & retail | 2024 |
| SRI Sampatti Ltd | Construction | 2024 |
| SRI SRI Tattva UK Ltd | Wholesale & retail | 2014 |
| Srifgndz Ltd | Hospitality | 2016 |
| Srkb Tech Ltd | Information & communication | 2024 |
| SRT Retail Ltd | Wholesale & retail | 2024 |
| SS & KS Consulting Ltd | Information & communication | 2018 |
| SSA Quality Care Limited | Health & social care | 2005 |
| SSG Capital Holdings Ltd | Financial services | 2026 |
| Sskannan Limited | Health & social care | 2023 |
| Sslm Consultancy Limited | Health & social care | 2013 |
| Sslm Properties Ltd | Real estate | 2024 |
| SSS Infotech Ltd | Information & communication | 2014 |
| ST Agnes EVE Limited | Extraterritorial | 2014 |
| ST Albans Storage Herts Ltd | Other services | 2023 |
| ST Andrews House Freehold Company Limited | Households | 2009 |
| ST Hildas Court 1971 Limited | Extraterritorial | 2015 |
| ST James' Stakeholder Holdings Limited | Information & communication | 2020 |
| ST Johns Breakers Ltd | Extraterritorial | 2016 |
| ST Mary's (Wendover) Limited | Wholesale & retail | 2005 |
| ST Peter Developments Limited | Real estate | 2015 |
| ST. Clarence Management Company Limited(The) | Real estate | 1986 |
| ST. John's Court (Cheltenham) Management Company Limited | Households | 1991 |
| ST. Judes Physiotherapy and Consulting Limited | Professional & scientific | 2002 |
| STA Aylesbury Ltd | Wholesale & retail | 2006 |
| Stable Shot Ltd | Professional & scientific | 2023 |
| Stablebridge Limited | Professional & scientific | 2010 |
| Stablemate Systems Limited | Information & communication | 1994 |
| Stag ROW Management Company Ltd | Households | 2020 |
| Stage Five Consulting Ltd | Professional & scientific | 2013 |
| Stage School of Dance Ltd | Arts & recreation | 2021 |
| Stage Showgirls Ltd | Arts & recreation | 2025 |
| Stak Performance Ltd | Arts & recreation | 2026 |
| Stamen Limited ZZ Ltd | Manufacturing | 2025 |
| Stand UP and Speak Ltd | Education | 2012 |
| Stanhome Management Company Limited | Households | 1989 |
| Stanhope Property Management Ltd | Real estate | 2025 |
| Stanley Pubs Properties Ltd | Real estate | 2023 |
| Stanstead Place Residents Limited | Households | 2019 |
| Stanton Technology Ltd | Administrative & support | 2014 |
| Star Business Management Ltd | Administrative & support | 2014 |
| Star Care 2 Ltd | Health & social care | 2023 |
| Star Film Services Limited | Information & communication | 2017 |
| Star Micronics Europe Limited | Manufacturing | 1982 |
| Star Quality Care and Support Limited | Administrative & support | 2024 |
| Star Travel Services Ltd | Transport & logistics | 2016 |
| Star Villa Holidays Ltd | Hospitality | 2013 |
| Starbank House Ltd | Other services | 2015 |
| Starboard Maritime Intelligence UK Limited | Information & communication | 2026 |
| Starbrook Chase (Fairford Leys) Management Company Limited | Households | 2001 |
| Stargaze Creator Network Limited | Professional & scientific | 2025 |
| Starkam Limited | Real estate | 2017 |
| Starlight Relocation Ltd | Professional & scientific | 2020 |
| Starling Consultancy Services Limited | Professional & scientific | 2020 |
| Starozi Limited | Professional & scientific | 2025 |
| Start UP Fuel Ltd | Administrative & support | 2014 |
| Startech Productions Limited | Information & communication | 1998 |
| Startpoint Management Company Limited | Households | 1982 |
| Startupuk Ltd | Professional & scientific | 2011 |
| Starveall Farm Limited | Administrative & support | 2014 |
| Stasia Capital UK Ltd | Real estate | 2011 |
| Statie Ltd | Wholesale & retail | 2016 |
| Station Court (Haddenham) Management Company Limited | Households | 1985 |
| Station Road (SM) Management Limited | Households | 2006 |
| Station Road 2021 LLP | | 2021 |
| Staunton Building Contractors Limited | Construction | 2002 |
| Stavordale Lodge Limited | Households | 1980 |
| Staykleen Commercial Cleaners Limited | Administrative & support | 2010 |
| STC Training Solutions Ltd | Health & social care | 2019 |
| Steak Corp Ltd | Hospitality | 2026 |
| Stealth Motor Sales Ltd | Wholesale & retail | 2025 |