| SRT Marine Systems PLC | Professional & scientific | 2005 |
| SRT Marine Technology Limited | Manufacturing | 2001 |
| SRT Property Limited | Real estate | 2019 |
| SRV Developments Ltd | Real estate | 2024 |
| ST Bathens Ltd | Hospitality | 2015 |
| ST Building and Renovation Ltd | Construction | 2014 |
| ST Catherine Valley Services Limited | Administrative & support | 2008 |
| ST Edwards Hall RTM Company Limited | Households | 2026 |
| ST John's Hospital Design and Build Ltd | Administrative & support | 2023 |
| ST John's Hospital Trading Company Ltd | Other services | 2013 |
| ST John's Hospital Trustee Limited | Professional & scientific | 2012 |
| ST Mark's Place Management Company Limited | Real estate | 2011 |
| ST Medical Services Ltd | Health & social care | 2018 |
| ST Michaels Reach Management Company Limited | Households | 2010 |
| ST Peter's Place Management Company Limited | Households | 2005 |
| ST Stephen's Allotments (Bath) Limited | Other services | 1999 |
| ST Swithins Yard Limited | Households | 2000 |
| ST. Martins Court (Bath) Limited | Households | 1981 |
| St.Stephens Court(Bath)Limited | Households | 1970 |
| ST8 (Investments) Limited | Real estate | 2006 |
| ST8 Limited | Construction | 2001 |
| Stabiliti Ltd | Information & communication | 2020 |
| Stable Focus Psychology Ltd | Health & social care | 2022 |
| Stacked & Stuffed Ltd | Hospitality | 2026 |
| Stacks Property Search London Limited | Real estate | 2015 |
| Stacks Relocation UK Limited | Real estate | 2004 |
| Stadiasmart Ltd | Professional & scientific | 2011 |
| Stafford Consulting Ltd | Professional & scientific | 2025 |
| Stall 54 Limited | Hospitality | 2009 |
| Stallion Company Limited | Real estate | 2024 |
| Stambrook Residential Mobile Home Park Ltd | Households | 2001 |
| Standard 8 & 10 Spares Limited | Wholesale & retail | 2013 |
| Standfast (Bristol) Limited | Extraterritorial | 1995 |
| Standout Beauty Ltd | Other services | 2023 |
| Stanley Catering Co. Ltd | Hospitality | 2017 |
| Stanners Golf Ltd | Wholesale & retail | 2024 |
| Stantonbury (Lydney) Limited | Construction | 2022 |
| Stantonbury (Mardy) Ltd | Construction | 2021 |
| Stantonbury (Oldland) Ltd | Construction | 2022 |
| Stantonbury Development (Melksham) Limited | Construction | 2020 |
| Stantonbury House Hair and Beauty Ltd | Other services | 2023 |
| Stanza Fitness Limited | Arts & recreation | 2018 |
| Stanza Group Ltd | Financial services | 2023 |
| Star Clean of Bath Limited | Administrative & support | 2004 |
| Star Hand Car Wash SS Ltd | Administrative & support | 2025 |
| Stardust Consultants Ltd | Professional & scientific | 2008 |
| Starfruit Socials Ltd | Information & communication | 2022 |
| Stargentus Limited | Professional & scientific | 2013 |
| Starion UK Limited | Professional & scientific | 1999 |
| Starline Group (Frome) Ltd | Transport & logistics | 2004 |
| Starline Taxis (Warminster) Limited | Transport & logistics | 2006 |
| Starr Architects Limited | Professional & scientific | 2025 |
| Starshell Ltd | Professional & scientific | 2012 |
| Starting Health Limited | Health & social care | 2017 |
| Starting Property Ltd | Households | 2023 |
| Starwalker Group Limited | Professional & scientific | 2023 |
| State School Industries Ltd | Education | 2024 |
| Station Meadows Apartments 2 Management Company Limited | Households | 2014 |
| Station Meadows Management Company Limited | Households | 2014 |
| Status Investments Ltd | Real estate | 2025 |
| Staverton Joinery Limited | Water & waste | 1966 |
| Stay Blue Sky Homes Ltd | Real estate | 2023 |
| Stay Original Company Ltd | Hospitality | 2010 |
| Stay Safe Fire Consultancy Ltd | Professional & scientific | 2023 |
| Steam Mill Properties Limited | Real estate | 2007 |
| Steam Mill Services Limited | Other services | 2010 |
| Steam Pink Collections Ltd | Wholesale & retail | 2025 |
| Steed Professional Services Limited | Health & social care | 2020 |
| Steel Media Limited | Information & communication | 2002 |
| Steers Mcgillan Lettings Ltd | Real estate | 2022 |
| Steersmcgillaneves Design Limited | Professional & scientific | 2009 |
| Stellasoft Limited | Information & communication | 2009 |
| Stellify Network Ltd | Information & communication | 2017 |
| Stemel Group Limited | Real estate | 2025 |
| Stemel Holdings Limited | Real estate | 2025 |
| Step-In Step-Out Learning and Development Solutions (S2LDS) Ltd | Education | 2011 |
| Stephen Fisher Investments Limited | Professional & scientific | 2008 |
| Stephen Flanagan Solutions Limited | Education | 2009 |
| Stephencsmith Ltd | Professional & scientific | 2026 |
| Stepping Stones Solar Ltd | Energy | 2023 |
| Sterling Capital Asset Finance Limited | Financial services | 2004 |
| Sterling Capital Holdings Ltd | Financial services | 2018 |
| Sterlo Limited | Energy | 2023 |
| Steve Forster Electrical Services Limited | Construction | 2007 |
| Steve Warren Transport Services Ltd | Transport & logistics | 2011 |
| Stewards Company Limited | Health & social care | 1898 |
| Stewart Hogg Consulting Limited | Professional & scientific | 2026 |
| STG Property Group Limited | Real estate | 2025 |
| Still Brothers Limited | Professional & scientific | 2024 |
| Stillpoint Bath Ltd | Health & social care | 2002 |
| Stillpoint Limited | Professional & scientific | 1990 |
| Stirtingale Ltd | Information & communication | 2015 |
| Stisma Limited | Wholesale & retail | 2026 |
| Stoic Enterprises Limited | Financial services | 2021 |
| Stokes Media Ltd | Information & communication | 2026 |
| Stolen Thunder Engineering Ltd | Wholesale & retail | 2019 |
| Ston Easton Park Estate Limited | Real estate | 2025 |
| Stone Hexagon Limited | Information & communication | 2012 |
| Stone King LLP | | 2005 |
| Stone King Trust Corporation Limited | Other services | 2022 |