| Sarajo Limited | Real estate | 2020 |
| Sarshot Limited | Extraterritorial | 1989 |
| Sash Enterprises Limited | Real estate | 2013 |
| Sash Property Holdings 1 Limited | Construction | 2023 |
| SAV Digital Solutions Ltd | Information & communication | 2026 |
| Sava Consultants Limited | Information & communication | 2013 |
| Savaya Investments Limited | Real estate | 2024 |
| Sawhney Property Ltd | Real estate | 2018 |
| Sawz Property Services Limited | Real estate | 1999 |
| SAY Goodnight Films Ltd | Information & communication | 2018 |
| SB Holdings (Group) Ltd | Financial services | 2023 |
| SB Restaurant Investments Ltd | Real estate | 2012 |
| SC Allen Properties Ltd | Hospitality | 2020 |
| Scanview Electronics Limited | Real estate | 1983 |
| Scard Retail Solutions Ltd | Professional & scientific | 2026 |
| Scene 2 B Limited | Other services | 2016 |
| Sceneography Ltd | Other services | 2011 |
| Science for Children Ltd | Education | 2014 |
| Scoresmatter Limited | Other services | 2011 |
| Scully Cooks Ltd | Hospitality | 2016 |
| Sculpt Studios Pilates Ltd | Arts & recreation | 2025 |
| SD Education Limited | Information & communication | 1987 |
| SDM Construction Services Limited | Construction | 2015 |
| Sea Production House Ltd | Arts & recreation | 2023 |
| Seaford Road Freehold Limited | Households | 2023 |
| Seapower (UK) Ltd. | Administrative & support | 1997 |
| Secret Project Productions Ltd | Information & communication | 2003 |
| Secretarial Ltd | Administrative & support | 2024 |
| Secure Rent Property Management Limited | Real estate | 2021 |
| Security Construction & Installation Services Ltd | Construction | 2024 |
| Seedless Invest Ltd | Financial services | 2024 |
| Seedra Ltd | Professional & scientific | 2019 |
| SEJ Homes Langley Ltd | Construction | 2020 |
| SEJ Homes Limited | Real estate | 2015 |
| SEJ Homes Partnership LLP | | 2024 |
| Selectafly Ltd. | Wholesale & retail | 2011 |
| Selective Credit Solutions Limited | Financial services | 1991 |
| Seofon Investments Limited | Households | 1958 |
| Serene Motors Ltd | Wholesale & retail | 2020 |
| Serenity Casa Ltd | Health & social care | 2023 |
| Serenity Seva Care Ltd | Financial services | 2023 |
| Serenroc Ltd | Information & communication | 2020 |
| Serliana Holdings Ltd | Construction | 2024 |
| SET & Scene Services Ltd | Information & communication | 2026 |
| Set-Craft Ltd | Other services | 2011 |
| Settle My Dispute Limited | Other services | 2014 |
| Setty Investments Ltd | Real estate | 2018 |
| Seventeen Recruitment Limited | Professional & scientific | 2020 |
| Severa Home Ltd | Professional & scientific | 2025 |
| SEY Property Limited | Real estate | 2021 |
| SFX Engineering Ltd | Information & communication | 2019 |
| SGG Manufacturing Limited | Manufacturing | 2003 |
| SH Investors Ltd | Real estate | 2024 |
| Shading Specialists Limited | Manufacturing | 2010 |
| Shadow Trading and Investments Limited | Information & communication | 2009 |
| Shadrack Productions Limited | Information & communication | 2006 |
| Shah Muqeem Developers UK Ltd | Construction | 2022 |
| Shakthi Construction & Maintenance Ltd | Construction | 2021 |
| Shakthi Consulting UK Limited | Construction | 2017 |
| Shakthi Investments UK Ltd | Real estate | 2018 |
| Shamsh Consultancy Limited | Wholesale & retail | 2017 |
| Sharcc Group Limited | Professional & scientific | 2025 |
| Sharde Investments Ltd | Real estate | 2003 |
| Sharox Investments Limited | Real estate | 2015 |
| Shaun Leane Beauty and Fragrance Ltd | Manufacturing | 2024 |
| Shaun Leane Group Ltd | Manufacturing | 2024 |
| Shaun Leane Jewellery Ltd | Manufacturing | 2024 |
| Shayona Medicare Holdings Limited | Financial services | 2025 |
| Shayona Medicare Limited | Wholesale & retail | 2023 |
| Sheen Clothing Ltd | Manufacturing | 2015 |
| Sheppard's Bespoke Building & Carpentry Limited | Construction | 2023 |
| Shift Solutions Limited | Wholesale & retail | 2020 |
| Shine Hotels & Housing Ltd | Hospitality | 2023 |
| Shiva OM Limited | Real estate | 2020 |
| Shivansh Medicare Limited | Wholesale & retail | 2025 |
| Shivneal Medicare Limited | Wholesale & retail | 2019 |
| Shivneet Medicare Limited | Wholesale & retail | 2021 |
| Shmc Solutions Ltd | Information & communication | 2026 |
| Shotopop Limited | Real estate | 2007 |
| Shoulder & Elbow 2016 Ltd | Health & social care | 2016 |
| Shoulder & Elbow Services Limited | Health & social care | 2006 |
| Shoulder Providers Limited | Health & social care | 2024 |
| Shoulder Services Limited | Health & social care | 2020 |
| Shreeji Medicare Limited | Wholesale & retail | 2018 |
| Shreeji Pharmacare Limited | Wholesale & retail | 2021 |
| Shutterbug Limited | Other services | 2006 |
| Sidhu Imperium (UK) Ltd | Professional & scientific | 2014 |
| Sidhu Niwas Limited | Real estate | 2014 |
| Sikh Dental Association (UK) Limited | Other services | 2020 |
| Silver Kite Scaffolding Ltd | Construction | 2016 |
| Silver Speck Limited | Information & communication | 2015 |
| Silverwing Properties Limited | Real estate | 2001 |
| Simbaridge Limited | Professional & scientific | 2019 |
| Simeio Limited | Information & communication | 2013 |
| Simmie Consulting Ltd | Information & communication | 2012 |
| Simon Bridbury Developments Limited | Professional & scientific | 1997 |
| Simon Bridbury Properties (ST. Albans) Limited | Real estate | 1994 |
| Simply Spyders Ltd | Manufacturing | 2012 |
| Simpsons Paints 2000 Limited | Wholesale & retail | 1999 |
| Simsan Investments Limited | Real estate | 2023 |