| SD Gynaecological Services Limited | Health & social care | 2016 |
| SDH (Bath) Limited | Professional & scientific | 2008 |
| SDK Plumbing and Heating Ltd | Construction | 2025 |
| SDR Tutoring Ltd | Education | 2017 |
| SE7EN Driving School Ltd | Education | 2025 |
| Sea Breeze (Aberdovey) Limited | Hospitality | 2008 |
| Sea Payroll Solutions Ltd | Professional & scientific | 2022 |
| Seacar Consulting Ltd | Professional & scientific | 2025 |
| Seadelion Ltd | Wholesale & retail | 2018 |
| Seagry Digital Ltd | Information & communication | 2021 |
| Seagry Enterprises Ltd | Financial services | 2021 |
| Search Markets Limited | Extraterritorial | 2020 |
| Searchlight Collections Limited | Administrative & support | 2012 |
| Searchlite Ltd | Information & communication | 2025 |
| Sears Consulting Limited | Professional & scientific | 2020 |
| Seasonal Beds Ltd | Administrative & support | 2013 |
| Seasonal Blooms Flower Company LLP | | 2021 |
| Seasons Publishing Limited | Information & communication | 2021 |
| Seccl Custody Limited | Financial services | 2016 |
| Seccl Technology Limited | Information & communication | 2016 |
| Secco Capital Limited | Financial services | 2024 |
| Secondleaf Ltd | Wholesale & retail | 2025 |
| Secret Garden Pre-School Limited | Education | 2026 |
| Secret Sauce GG Ltd | Information & communication | 2024 |
| Securenet-World Ltd | Information & communication | 2025 |
| Sedgemoor Property Bath Ltd | Real estate | 2026 |
| Sedgwick White Limited | Professional & scientific | 2021 |
| SEE + Quin Limited | Manufacturing | 2020 |
| SEE Blue Limited | Professional & scientific | 2009 |
| See-Blue Marketing Ltd | Professional & scientific | 2019 |
| Seed Landscape Design Limited | Other services | 2006 |
| Seed Travel Ltd | Administrative & support | 2020 |
| Seisai Ltd | Information & communication | 2023 |
| Seismi Limited | Information & communication | 2009 |
| Selby Landscapes Limited | Administrative & support | 2017 |
| Select Partnerships (Capital Investment) Ltd | Financial services | 2024 |
| Select Security & Maintenance Services Limited | Administrative & support | 2011 |
| Select Sounds Inc Ltd | Arts & recreation | 2022 |
| Selectscience Limited | Information & communication | 1998 |
| Self Haus Ltd | Information & communication | 2026 |
| Selina Tomlinson Partnership Ltd | Health & social care | 2023 |
| Sellr Ltd | Information & communication | 1999 |
| Selway Court Management Company Limited | Households | 1990 |
| SEN Navigator Ltd | Information & communication | 2025 |
| Senanque Limited | Professional & scientific | 2016 |
| Sendrato PAY UK Ltd | Hospitality | 2025 |
| Sense Enabling Mindfulness CIC | Health & social care | 2024 |
| SENSES8 Ltd | Other services | 2023 |
| Sensoriot Ltd | Manufacturing | 2022 |
| Sentient OS Ltd | Information & communication | 2026 |
| September Spaces Ltd | Real estate | 2024 |
| Seqestra Limited | Agriculture & fishing | 2025 |
| Sequest Limited | Professional & scientific | 2019 |
| Seraphel Medical Ltd | Wholesale & retail | 2025 |
| Serena Bolton Photography Limited | Professional & scientific | 2021 |
| Serenade Adventures Ltd | Hospitality | 2024 |
| Serenport Limited | Real estate | 2023 |
| Serious Solutions Developments Limited | Construction | 2011 |
| Session Zero Films Limited | Information & communication | 2025 |
| SET Etiquette Ltd | Education | 2019 |
| SET on the Floor Limited | Information & communication | 2014 |
| Setsquared Limited | Administrative & support | 2020 |
| Seule Limited | Manufacturing | 2025 |
| Sevco 1124 Limited | Real estate | 2000 |
| Seven Hills (Bath) Limited | Manufacturing | 2012 |
| Seven to Twelve Ltd | Real estate | 2022 |
| Seventy Four St.Pauls Road Management Limited | Households | 1987 |
| Seyed Power Electronics (SPE) Ltd | Professional & scientific | 2025 |
| Seymour Events Limited | Administrative & support | 2018 |
| Seymour Security Ltd | Administrative & support | 2021 |
| Seymour Travels Ltd | Administrative & support | 2020 |
| SG Aerospace (UK) Limited | Professional & scientific | 1972 |
| SG Construction (Bath) Ltd | Construction | 2026 |
| Sgcns Ltd | Administrative & support | 2024 |
| Sgpa Holdings Limited | Real estate | 2025 |
| SGS Infotech Limited | Information & communication | 2014 |
| Shackleton Films Ltd | Information & communication | 2021 |
| Shadowfax Insights Limited | Professional & scientific | 2024 |
| Shail Eric Limited | Manufacturing | 2017 |
| Shail Lettings Limited | Real estate | 2020 |
| Shail Property Services Ltd | Construction | 2020 |
| Shaken Milk Productions Ltd | Information & communication | 2021 |
| Shaker & MAY Limited | Manufacturing | 2020 |
| Shakespeare Hospitality Limited | Hospitality | 2024 |
| Shakeup Cosmetics Limited | Wholesale & retail | 2018 |
| Shane Egan Ltd | Administrative & support | 2010 |
| Shared Ground Ltd | Professional & scientific | 2026 |
| Sharegov Ltd | Hospitality | 2016 |
| Shark Opciones LLP | | 2009 |
| Shark River Consulting Limited | Professional & scientific | 2022 |
| Sharland Consultancy Limited | Administrative & support | 2022 |
| Sharp Family Law Limited | Professional & scientific | 2015 |
| Sharratt Interim Management Services Ltd | Professional & scientific | 2023 |
| Shaw London Ltd | Wholesale & retail | 2018 |
| Shaw's Roofing & Guttering Limited | Construction | 2025 |
| SHC Tiling Limited | Construction | 2011 |
| Shcl Limited | Professional & scientific | 2006 |
| Shearn Group Ltd | Wholesale & retail | 2023 |
| Sheerluxe Limited | Information & communication | 2007 |
| Sheetal Ltd | Health & social care | 2025 |