| SD Smart Software Limited | Information & communication | 2010 |
| SDC Healthcare Limited | Health & social care | 2016 |
| Sdhnc Ltd | Professional & scientific | 2022 |
| Sdisl Ltd | Real estate | 2022 |
| SDN Glazing Ltd | Construction | 2024 |
| SDP Investments Limited | Real estate | 2025 |
| SDS Consulting Limited | Administrative & support | 2014 |
| SE Security Electrical Ltd | Construction | 2024 |
| Sea.Black Limited | Wholesale & retail | 2019 |
| Seaa Energy Pharmatech Ltd | Professional & scientific | 2026 |
| Seagrove Engineering Ltd | Construction | 2020 |
| Seantoby Limited | Manufacturing | 2010 |
| Search Craft Ltd | Professional & scientific | 2016 |
| Sears Morgan Property Management Limited | Administrative & support | 2006 |
| Season House Limited | Wholesale & retail | 2024 |
| Seaton Limited | Real estate | 2018 |
| Sebalance Group Ltd | Professional & scientific | 2025 |
| Sebastian Sternberg Ltd | Information & communication | 2010 |
| Secinnovate Limited | Education | 2015 |
| Second Name Agency Limited | Professional & scientific | 2021 |
| Second Transport Company LLP | | 2012 |
| Secret Scent Trading Ltd | Wholesale & retail | 2024 |
| Secrets of Nature Ltd | Wholesale & retail | 2024 |
| Sector Nine Investments Limited | Real estate | 2010 |
| Secucap Limited | Information & communication | 2015 |
| Secur-Tec Services Ltd | Professional & scientific | 2013 |
| Secure FX Limited | Administrative & support | 2011 |
| Secure Motors International Ltd | Wholesale & retail | 2024 |
| Secure Property Ltd | Real estate | 2018 |
| Secure Stride Ltd | Administrative & support | 2025 |
| SECURE365 Ltd | Information & communication | 2008 |
| Secured Holdings Ltd | Financial services | 2021 |
| Securities and Banking Consulting Limited | Information & communication | 2008 |
| Security and Cleaning Limited | Administrative & support | 2024 |
| Security Design & Development Limited | Administrative & support | 1990 |
| Sedawk Technology Services Limited | Information & communication | 2012 |
| Sedenion Limited | Wholesale & retail | 2011 |
| Sedivcharan Limited | Information & communication | 2009 |
| Sedum Silver Ltd | Real estate | 2019 |
| SEE the Rabbit Productions Ltd | Information & communication | 2025 |
| Seee Holdings Ltd | Financial services | 2020 |
| Seele Nova Ltd | Education | 2025 |
| Seepbas Energy Limited | Professional & scientific | 2019 |
| Seesave Limited | Information & communication | 2012 |
| Sefis LP | | 2017 |
| Sefk Limited | Professional & scientific | 2013 |
| Sefra Capital Ltd | Professional & scientific | 2025 |
| Segini Medical Limited | Health & social care | 2018 |
| Sekforde Drinks Limited | Manufacturing | 2016 |
| Sekogt Investments Limited | Financial services | 2025 |
| Sekura Services Ltd | Construction | 2021 |
| Select Auto Solutions Ltd | Wholesale & retail | 2024 |
| Select Holdings Group Limited | Administrative & support | 2020 |
| Selena Group LLP | | 2021 |
| Self Development Mastery Ltd | Education | 2023 |
| Selfide Limited | Information & communication | 2019 |
| Selina's Kitchen Limited | Extraterritorial | 2005 |
| Selkie Chocolate Limited | Manufacturing | 2025 |
| Sell & Style Limited | Wholesale & retail | 2024 |
| Selma Felton Limited | Professional & scientific | 2012 |
| Selworthy Properties Ltd | Real estate | 2025 |
| SEM Literature Club Ltd | Education | 2026 |
| SEM Tuition Ltd | Education | 2024 |
| Semaphore Ltd | Information & communication | 2022 |
| Sematide Services Limited | Information & communication | 2022 |
| Sembi Limited | Professional & scientific | 2024 |
| Semfa Engineering Limited | Administrative & support | 2008 |
| Semimetrics Limited | Manufacturing | 1992 |
| Seminel Property Ltd | Real estate | 2019 |
| Semper Porro Property Maintenance Ltd | Construction | 2026 |
| Senait Mamo Limited | Health & social care | 2015 |
| Senara Ltd | Hospitality | 2017 |
| Senatecastle Limited | Households | 1977 |
| Send Education for ALL Ltd | Education | 2024 |
| Send Shield Limited | Information & communication | 2025 |
| Seneca Designs Limited | Information & communication | 2014 |
| Senikma Natural Foods UK Ltd | Wholesale & retail | 2023 |
| Senshun Ltd | Real estate | 2023 |
| Sensia Torsion Holdco Limited | Health & social care | 2026 |
| Sensorvale Limited | Administrative & support | 2016 |
| Sentario UK Limited | Information & communication | 2023 |
| Sentido Global Business Limited | Real estate | 2011 |
| Sentienz Limited | Information & communication | 2018 |
| Sentinal Property Ltd | Real estate | 2021 |
| Sentinel Broadcast Ltd | Wholesale & retail | 2002 |
| Sentinel Scaffolding Services Ltd | Construction | 2017 |
| Sentinel Ware Limited | Information & communication | 2016 |
| Sentinelex Ltd | Information & communication | 2025 |
| Sentis Management Company Limited | Households | 1986 |
| Sentry Aerospares Holdings Limited | Financial services | 2019 |
| Sentry Aerospares Limited | Transport & logistics | 2000 |
| Sentry Group Holdings Limited | Financial services | 2024 |
| SEP Polythene Ltd | Wholesale & retail | 2019 |
| Septelici Ltd | Construction | 2017 |
| Septoo Limited | Information & communication | 2023 |
| Seqtx Ltd | Professional & scientific | 2025 |
| Sequence Catering Ltd. | Administrative & support | 2018 |
| Sequoia Seed Productions Ltd | Arts & recreation | 2025 |
| Serac Consultancy Ltd | Information & communication | 2018 |
| Serandib Limited | Education | 2021 |