| S.P. Holmes Groundworks Limited | Construction | 2025 |
| S.W.A.T Forge Airsoft Ltd | Wholesale & retail | 2025 |
| S1WK Limited Liability Partnership | | 2025 |
| S2S Healthcare Ltd | Administrative & support | 2024 |
| S5 Basketball Limited | Wholesale & retail | 2023 |
| SA Rise Consulting Limited | Information & communication | 2019 |
| Saayee QA Services Limited | Information & communication | 2012 |
| Sabas Enterprises Ltd | Hospitality | 2019 |
| Sable Media Solutions Limited | Information & communication | 2009 |
| Sabre Solutions Limited | Information & communication | 2004 |
| Sabrina Drou Coaching Limited | Administrative & support | 2021 |
| Sacha Hourigan Equipe Saddles Limited | Wholesale & retail | 2023 |
| Sacrifice Films Limited | Information & communication | 2024 |
| Sacrifice Holdings Limited | Information & communication | 2024 |
| Sadais Ltd | Health & social care | 2023 |
| Sael Projects Limited | Real estate | 2019 |
| Safco Alternative Asset Services Ltd | Administrative & support | 2012 |
| Safe and Sound Premium Collectible Cases Ltd | Manufacturing | 2025 |
| Safe Choice Care Ltd | Health & social care | 2017 |
| Safe Hands (Surrey) Ltd | Other services | 2020 |
| Safescan Limited | Wholesale & retail | 2017 |
| Safety Compliance Solutions Ltd | Professional & scientific | 2011 |
| Safety First Consultants (London) Limited | Education | 1995 |
| Safety Flooring Supplies | | 2009 |
| Safety Inspections (Uk-Se) Limited | Professional & scientific | 2022 |
| Safety on Site Limited | Professional & scientific | 2022 |
| Saffron (Medway) Limited | Hospitality | 2010 |
| Saffron Asset Finance Ltd | Financial services | 2005 |
| Saffron Developments (Medway) Ltd | Real estate | 2020 |
| Saffron Financial Limited | Financial services | 2020 |
| Saffron Vision Limited | Health & social care | 2024 |
| Safion Care Ltd | Health & social care | 2017 |
| Sagarti Private Ltd | Real estate | 2023 |
| Sagittarius Media Limited | Manufacturing | 2001 |
| Sahib & Co. Ltd | Professional & scientific | 2013 |
| SAI Accounting and Business Consultants Limited | Professional & scientific | 2023 |
| SAI Medical Services Ltd | Health & social care | 2019 |
| SAI Properties Investment Ltd | Real estate | 2019 |
| SAI Properties Services Ltd | Real estate | 2018 |
| Saib Canal Ltd | Construction | 2019 |
| Saib Co. (London) Ltd | Professional & scientific | 2019 |
| Saiga Systems Ltd. | Extraterritorial | 2023 |
| Saik Enterprises Ltd | Real estate | 2018 |
| Sailfin Ltd | Information & communication | 2007 |
| Sailing Days Management Limited | Professional & scientific | 2010 |
| Sailing Leyla Ltd | Extraterritorial | 2024 |
| Saimbi Properties Limited | Real estate | 2019 |
| Saint Stone Investment Limited | Real estate | 2026 |
| Saintborn Limited | Construction | 2018 |
| Sairamana Software Technologies Limited | Information & communication | 2013 |
| SAK Electrical Ltd | Construction | 2020 |
| Salad Ltd | Hospitality | 2024 |
| Salanjesiniakellinah Limited | Health & social care | 2020 |
| Saleh Properties Ltd | Real estate | 2024 |
| Salek Tyres and Mechanics Ltd | Wholesale & retail | 2024 |
| Salesvida Ltd | Information & communication | 2026 |
| Salhan Services Limited | Construction | 2025 |
| Salihu Construction Ltd | Construction | 2023 |
| Salus Community Limited | Extraterritorial | 2013 |
| Salus Platform Ltd | Professional & scientific | 2025 |
| Salus Solutions Ltd | Education | 2011 |
| Salvatori Property Investments Limited | Real estate | 2016 |
| Salvor Limited | Financial services | 2024 |
| SAM Bassant Accountancy Services Limited | Professional & scientific | 2018 |
| SAM Diamond Home Solution Ltd | Construction | 2017 |
| Samantha Beeny Freelance Limited | Professional & scientific | 2025 |
| Samantha Pantha Ltd | Professional & scientific | 2014 |
| Samba Aesthetics Limited | Other services | 2021 |
| Sambm Spice Ltd | Hospitality | 2026 |
| Samdams Limited | Health & social care | 2017 |
| Samdebs Amazing Grace Kids Limited | Health & social care | 2018 |
| Samiz Lounge Hair & Beauty Ltd | Other services | 2021 |
| Sammy Property Ltd | Real estate | 2025 |
| Samona Limited | Information & communication | 2008 |
| Samreen Transport Ltd | Transport & logistics | 2019 |
| Samsara OIL Ltd | Wholesale & retail | 2023 |
| Samuel Building RJJ Ltd | Construction | 2024 |
| Samuel Investments Ltd | Real estate | 2022 |
| SAN Remo Management Limited | Real estate | 2001 |
| Sanare Limited | Professional & scientific | 2012 |
| Sandbanks Property Ltd | Real estate | 2018 |
| Sandbar Investments Limited | Wholesale & retail | 2015 |
| Sandells Holdings Limited | Professional & scientific | 1988 |
| Sandells Maintenance Limited | Construction | 1988 |
| Sandeman (Biddenden) Management Limited | Administrative & support | 2015 |
| Sanderling Psychology Limited | Health & social care | 2024 |
| Sandhurst Garden Services Ltd | Administrative & support | 2020 |
| Sandstone Creative Ltd | Professional & scientific | 2024 |
| Sandy Bay Leisure Limited | Hospitality | 2003 |
| Sandy Lane Commercial Limited | Real estate | 2023 |
| Sanghera Construction Ltd | Construction | 2020 |
| Sanghera Real Estates Ltd | Real estate | 2023 |
| Saniclean Services LP | | 2010 |
| Sanity Arms Ltd | Wholesale & retail | 2026 |
| Sankara Ltd | Real estate | 2021 |
| Sannton Ltd | Construction | 2014 |
| Sanquhar Enterprises Limited | Education | 1961 |
| Sansa Automotive Ltd | Wholesale & retail | 2024 |
| Sansa Car Hire Ltd | Administrative & support | 2025 |
| Sansa London Ltd | Wholesale & retail | 2022 |