| Sean Curry Ltd | Health & social care | 2012 |
| Seavision Films Limited | Information & communication | 2024 |
| Sebinstall Ltd | Construction | 2017 |
| Second Fit Ltd | Construction | 2017 |
| Secret Love Joy Limited | Wholesale & retail | 2016 |
| Secure Electrical Engineering Ltd | Construction | 2018 |
| Secure Pathways Ltd | Health & social care | 2025 |
| Secured Electrics Ltd | Construction | 2018 |
| Secured Training Ltd | Professional & scientific | 2020 |
| Securepoint Security Ltd | Administrative & support | 2025 |
| Securetech Corporation Ltd | Information & communication | 2010 |
| Securewall Ltd | Professional & scientific | 2025 |
| Security Dynamics (Europe) Ltd | Wholesale & retail | 2011 |
| Security Xpress Ltd | Professional & scientific | 2007 |
| SEE Easy Ltd | Wholesale & retail | 2024 |
| SEE ME Salon Ltd | Other services | 2022 |
| SEE Properties Living Ltd | Real estate | 2024 |
| SEE Property Holdings Ltd | Real estate | 2019 |
| SEE World Ltd | Administrative & support | 2010 |
| Seedbuckets Ltd | Information & communication | 2024 |
| Seeds International for Investment and Development Ltd | Financial services | 2021 |
| Seeefi Limited | Health & social care | 2018 |
| Seek Homecare Ltd | Health & social care | 2022 |
| Seforged Ltd | Wholesale & retail | 2025 |
| Seima Medical Limited | Health & social care | 2012 |
| SEJ Supplies Ltd | Wholesale & retail | 2018 |
| Sejza Property Solutions Ltd | Households | 2025 |
| Sekai Holdings Limited | Financial services | 2023 |
| Sekemi Limited | Health & social care | 2022 |
| Select Consulting Ltd | Professional & scientific | 2019 |
| Select Partnership Ltd | Real estate | 2016 |
| Select the MAN Ltd | Information & communication | 2021 |
| Selekt Pizza Inn Ltd | Hospitality | 2018 |
| Self (Self Education & Learning Framework) Ltd | Health & social care | 2022 |
| Self Drive Cars Limited | Wholesale & retail | 2026 |
| Selfmade NH Limited | Administrative & support | 2018 |
| Sellenis Limited | Professional & scientific | 2009 |
| Selwyn Court (Wembley) Ltd | Households | 2010 |
| Sema Living Limited | Hospitality | 2024 |
| Senaj Properties Ltd | Construction | 2016 |
| Senator Enterprises Limited | Wholesale & retail | 2008 |
| Senator's Limited | Real estate | 2024 |
| Sensa Joinery Limited | Construction | 2017 |
| Sense Electra LP | | 2021 |
| Senshi Judo Club Limited | Health & social care | 2019 |
| Sensol Ltd | Information & communication | 2025 |
| Sentient Tech Ltd | Construction | 2026 |
| Sentinel FX Limited | Financial services | 2024 |
| Sentrex Ltd | Construction | 2025 |
| Seo-Ux Design Ltd | Information & communication | 2021 |
| Seon IT Ltd | Information & communication | 2026 |
| Seraphine Estates Ltd | Real estate | 2026 |
| Seraphinne Vallora Ltd | Information & communication | 2025 |
| Serenity One Ltd | Health & social care | 2018 |
| Serenity Steps Ltd | Health & social care | 2023 |
| Serenity Suites Ltd | Health & social care | 2023 |
| Serenity Therapies Limited | Other services | 2019 |
| Sergej Autos Limited | Wholesale & retail | 2011 |
| Sergiu&Oana Ltd | Administrative & support | 2022 |
| Serial Shopper Ltd | Wholesale & retail | 2021 |
| Servetronic Ltd | Information & communication | 2009 |
| Serviced Apartment London Ltd | Real estate | 2021 |
| Services & Business London Ltd | Information & communication | 2016 |
| Sethi Prabh Ltd | Real estate | 2023 |
| Seven Summits Studio Ltd | Information & communication | 2021 |
| SEVENTY8 Housing Solutions Limited | Real estate | 2021 |
| Sevring Limited | Real estate | 2000 |
| Sevring One Limited | Real estate | 2010 |
| Sexi Walls Design Ltd | Construction | 2015 |
| Seycure Ltd | Construction | 2025 |
| Seymour and Co Limited | Wholesale & retail | 2013 |
| Sfdp Investment Limited | Real estate | 2021 |
| Sfdp Limited | Health & social care | 2018 |
| SG Infinity Limited | Real estate | 2023 |
| SG Marketplace UK Limited | Wholesale & retail | 2023 |
| SG62HOL Ltd | Real estate | 2025 |
| SG62OP Ltd | Real estate | 2025 |
| SGA Group Limited | Health & social care | 2021 |
| Sgmn Ltd | Financial services | 2024 |
| SGN Property 2 Ltd | Real estate | 2023 |
| SGN Property Investments Ltd | Real estate | 2019 |
| SGP Retail Ltd | Wholesale & retail | 2023 |
| SGR Real Estate Holdings Ltd | Real estate | 2021 |
| Sgwp Limited | Construction | 2025 |
| SH & LH Properties Limited | Real estate | 2023 |
| SH Plumbing & Heating Services Limited | Construction | 2016 |
| SH08 Limited | Administrative & support | 2008 |
| SHA Security Co. Ltd | Other services | 2007 |
| Shaam Restaurant Ltd | Hospitality | 2016 |
| Shabz Developments Ltd | Construction | 2026 |
| Shada Traders Limited | Wholesale & retail | 2023 |
| Shade and Shield Customz Ltd | Wholesale & retail | 2026 |
| Shade and Shield Detailing Ltd | Wholesale & retail | 2026 |
| Shade and Shield Wraps Ltd | Wholesale & retail | 2026 |
| Shaded Canvas Ltd | Information & communication | 2023 |
| Shadow I.N.C. Records Ltd | Information & communication | 2010 |
| Shah Hospitality Ltd | Hospitality | 2026 |
| Shah JEE Group Ltd | Real estate | 2023 |
| Shah Law Chambers Ltd | Professional & scientific | 2021 |
| Shah UK Traders Ltd | Wholesale & retail | 2026 |