| Shepherds Hall Management Company (1995) Limited | Households | 1995 |
| Sheraton Carriers Ltd | Transport & logistics | 2026 |
| Sherlok Homes Properties Limited | Real estate | 2012 |
| Shermore Properties Limited | Real estate | 2025 |
| Shevchuk Ltd | Financial services | 2025 |
| Shield Bidco Limited | Financial services | 2021 |
| Shield Safety Consultancy Ltd | Construction | 2019 |
| Shield Security Trustee Limited | Financial services | 2021 |
| Shield Topco Limited | Financial services | 2021 |
| Shift Active Media Limited | Professional & scientific | 2010 |
| Shilpi Management Ltd | Real estate | 2012 |
| Shimao Limited | Financial services | 2015 |
| Shindig Productions Ltd | Arts & recreation | 2014 |
| Shindig Trading Limited | Arts & recreation | 2015 |
| Shining Qualities Ltd | Wholesale & retail | 2020 |
| Shire Aero Tech Limited | Wholesale & retail | 2011 |
| Shire Civils Limited | Wholesale & retail | 2011 |
| Shirinn Ltd | Manufacturing | 2023 |
| Shjc Holdings Limited | Financial services | 2011 |
| Shooz Limited | Manufacturing | 2015 |
| Shoppable Interiors Ltd | Professional & scientific | 2025 |
| Showco One Limited | Arts & recreation | 2022 |
| Showco Two Limited | Arts & recreation | 2022 |
| Shree Jagannatha Temple (NON Profit) Community Interest Company | Other services | 2020 |
| Shree Medical Practice Limited | Health & social care | 2023 |
| Shreetejaji Properties Ltd | Real estate | 2025 |
| Shrewsbury Energy Ltd | Energy | 2022 |
| Shri Gaia Limited | Health & social care | 2024 |
| SHU Architects Limited | Professional & scientific | 2019 |
| Sibex Hunting Ltd | Information & communication | 2025 |
| Sicolowebb Architects Ltd | Professional & scientific | 2019 |
| Siddons House Limited | Households | 2024 |
| Sideline Investments Limited | Real estate | 2000 |
| Siena Group Limited | Real estate | 2020 |
| Sienna Systems Ltd | Administrative & support | 2014 |
| Sierra Vista Capital Limited | Real estate | 2015 |
| Sietar UK | Education | 2014 |
| SIGHT4SPORT Limited | Wholesale & retail | 2005 |
| Sightline Landscape Ltd | Professional & scientific | 2014 |
| Signalyard Ltd | Professional & scientific | 2013 |
| Signature Fabrics Holdings Limited | Financial services | 2024 |
| Signum Stallions Ltd | Agriculture & fishing | 2026 |
| Sild Media Limited | Information & communication | 2022 |
| Silent K Media Ltd | Information & communication | 2022 |
| Silky Ltd | Professional & scientific | 2019 |
| Silph Co Ltd | Professional & scientific | 2025 |
| Silsden Boats (Holidays) Limited | Extraterritorial | 2001 |
| Silsden Boats Limited | Extraterritorial | 2001 |
| Silvan Architects Ltd | Professional & scientific | 2022 |
| Silver Rock Masonry Limited | Manufacturing | 2025 |
| Silver Water Limited | Professional & scientific | 2008 |
| Silverfox Lifestyle Limited | Other services | 2011 |
| Silverpoint Properties Limited | Financial services | 1999 |
| Silvy's Pizza Company Ltd | Hospitality | 2021 |
| Simecology Limited | Professional & scientific | 2005 |
| Simibrum Limited | Information & communication | 2020 |
| Simmergy Ltd | Professional & scientific | 2016 |
| Simon Bush Ltd | Real estate | 2011 |
| Simon Crowe Ltd | Professional & scientific | 2013 |
| Simon Johnson Landscape & Garden Design Ltd | Professional & scientific | 2021 |
| Simon Morray-Jones Architects Limited | Professional & scientific | 2013 |
| Simon Rayner Architecture LLP | | 2018 |
| Simpact C.I.C. | Professional & scientific | 2015 |
| Simpatico Medical Limited | Education | 2012 |
| Sinapi Biomedical UK Ltd | Wholesale & retail | 2023 |
| Sincere Products & Services Ltd | Information & communication | 2021 |
| Sinclair Dalby Limited | Professional & scientific | 2011 |
| Sinclair Elliot Limited | Professional & scientific | 2015 |
| Sinclair Properties (Bath) Limited | Real estate | 2024 |
| Sinden Consulting Ltd | Professional & scientific | 2019 |
| Sindi Mhlanga Ltd | Health & social care | 2011 |
| Sion Hill Place Bath LLP | | 2019 |
| Siri Capital Limited | Financial services | 2021 |
| SIX Eight Nine Consultancy Limited | Professional & scientific | 2021 |
| SIX LPW Bath Ltd | Real estate | 1976 |
| Sixty One Walcot Ltd | Wholesale & retail | 2018 |
| SJ Green Tech Ltd | Health & social care | 2025 |
| SJ Pope Holdings Ltd | Financial services | 2023 |
| SJP Performance Ltd | Arts & recreation | 2024 |
| SK Nominees Ltd | Extraterritorial | 2013 |
| SK Secretary Limited | Administrative & support | 1997 |
| Skardon IFA Ltd | Financial services | 2021 |
| SKD Loft Conversion Specialists Limited | Construction | 2013 |
| Skeletal Software Limited | Information & communication | 2001 |
| Skeleton AMY Limited | Professional & scientific | 2010 |
| SKG Consulting Services Ltd | Professional & scientific | 2026 |
| SKM Life Sciences Limited | Professional & scientific | 2016 |
| Skogen Drinks Ltd | Manufacturing | 2023 |
| Skogen Limited | Hospitality | 2016 |
| Sky Estates Europe Limited | Financial services | 2014 |
| Sky High Confidence Limited | Health & social care | 2014 |
| Sky Interiors (Bath) Limited | Professional & scientific | 2013 |
| Skyestates & Properties Ltd | Real estate | 2024 |
| Skyline Automotive Limited | Wholesale & retail | 2025 |
| Skyline Investments Group Limited | Real estate | 2023 |
| Skysense Ltd | Real estate | 2019 |
| SL Oncology Limited | Health & social care | 2021 |
| Sladebrook IT Consultancy Limited | Administrative & support | 2012 |
| Slam Collective Ltd | Arts & recreation | 2026 |
| Slee Property Group Limited | Real estate | 2017 |