| Seneca Homes Ltd | Real estate | 2021 |
| Seneca Property Services Ltd | Manufacturing | 2025 |
| Senior Help South Limited | Administrative & support | 2018 |
| Senma Global Ltd | Manufacturing | 2025 |
| Sennen Estates Ltd | Real estate | 2010 |
| Sensation Entertainment Consultancy Ltd | Arts & recreation | 2017 |
| Sensations Holloway RD Ltd | Manufacturing | 2014 |
| Sensei Limited | Wholesale & retail | 2016 |
| Sensiphi Ltd | Manufacturing | 2024 |
| Sentinel Care Services Limited | Health & social care | 2026 |
| Senzu Healthtech Ltd | Information & communication | 2021 |
| SEO Genesis Ltd | Information & communication | 2025 |
| SEO Strategy Ltd | Professional & scientific | 2021 |
| Seocast Ltd | Information & communication | 2023 |
| Sequence Media Limited | Information & communication | 2004 |
| Sequentec Ltd | Manufacturing | 2015 |
| Sequentia Limited | Real estate | 1981 |
| Sequoia Resource Limited | Administrative & support | 2018 |
| Serafimcmm Ltd | Professional & scientific | 2018 |
| Serandib Wellness UK Limited | Administrative & support | 2025 |
| Seraphina Investments Ltd | Real estate | 2016 |
| Serene Aesthetics (Hereford) Ltd | Health & social care | 2019 |
| Serene Skin Ltd | Other services | 2019 |
| Serene Water Head Spa Ltd | Other services | 2026 |
| Serenelle Sleep Ltd | Wholesale & retail | 2025 |
| Serenice Limited | Wholesale & retail | 2025 |
| Serenity Chemicals Limited | Wholesale & retail | 2021 |
| Serenity Children Services Limited | Health & social care | 2023 |
| Serenity Heal Ltd | Health & social care | 2024 |
| Serenity Supplements Ltd | Manufacturing | 2025 |
| Serenkai Business Automations Limited | Information & communication | 2025 |
| Serenkai Group Limited | Financial services | 2025 |
| Serenkai Maritime Services Limited | Professional & scientific | 2025 |
| Serenleaf Ltd | Wholesale & retail | 2026 |
| Serenvest Limited | Financial services | 2018 |
| Sergeant and Holliday PUB Co Limited | Hospitality | 2016 |
| Serious FUN Children's Network International | Health & social care | 2014 |
| Servan Barbers Limited | Other services | 2021 |
| Serveaero Limited | Wholesale & retail | 2016 |
| Servercare Limited | Information & communication | 2024 |
| Service and Maintenance Ltd | Construction | 2022 |
| Service Charge Accounting Solutions Limited | Professional & scientific | 2020 |
| Service Heating and Bathrooms Ltd | Construction | 2018 |
| Serving Tennis Limited | Arts & recreation | 2006 |
| Serwat Ltd | Information & communication | 2026 |
| SES Carpentry Ltd | Construction | 2020 |
| SES Environmental Services Limited | Professional & scientific | 2025 |
| Sesi Ltd | Construction | 2025 |
| Seski Ltd | Transport & logistics | 2016 |
| SET Masters Ltd | Information & communication | 2025 |
| Set-Point Services Limited | Manufacturing | 1999 |
| Setford and Company (London) Limited | Wholesale & retail | 2023 |
| Setford and Company Limited | Wholesale & retail | 2010 |
| Seve Ltd | Transport & logistics | 2016 |
| Seven Contractors Limited | Construction | 2019 |
| Seven Group Capital Limited | Financial services | 2024 |
| Seven Monument Limited | Real estate | 2013 |
| Seven Two Seven Four Ltd | Real estate | 2021 |
| Seventeen Days Limited | Administrative & support | 2022 |
| Seventh Sister Ltd | Manufacturing | 2024 |
| Seventy Seven Normal Limited | Other services | 2018 |
| Sevioa Ltd | Real estate | 2026 |
| SEW Easy Limited | Manufacturing | 2003 |
| SEW Shack Ltd | Manufacturing | 2025 |
| SF Furniture Homeland Limited | Wholesale & retail | 2018 |
| SF6 Recovery Ltd | Professional & scientific | 2019 |
| SFG Group Limited | Financial services | 2015 |
| SFS Cruise Logistics Ltd | Transport & logistics | 2009 |
| SFS Trading Co Limited | Transport & logistics | 2019 |
| SFW Management Limited | Real estate | 2012 |
| SG Innovation Ltd | Information & communication | 2025 |
| SG Management Limited | Professional & scientific | 2023 |
| SG Nexus Logistic Ltd | Transport & logistics | 2026 |
| SG PVT Ltd | Transport & logistics | 2026 |
| SG Service Holdings Limited | Extraterritorial | 2024 |
| SGB Property Ltd. | Extraterritorial | 2022 |
| SGC Projects Limited | Construction | 2003 |
| SGJ Services Ltd | Construction | 2024 |
| SGL Accounting Ltd | Professional & scientific | 2015 |
| SGM Electrical Services Ltd | Construction | 2015 |
| SGS Delivery Ltd | Transport & logistics | 2019 |
| Sgsi Limited | Hospitality | 2024 |
| SGT Paving Ltd | Construction | 2021 |
| SH Garden Care Ltd | Professional & scientific | 2022 |
| SH Mechanical Services Ltd | Construction | 2013 |
| SH UK Construction Limited | Construction | 2015 |
| SHA Express Ltd | Transport & logistics | 2024 |
| Sha-Daze Ltd | Administrative & support | 2019 |
| Shackle's Ships Limited | Arts & recreation | 2021 |
| Shackleton House Apartments Limited | Real estate | 2018 |
| Shadelar Ltd | Other services | 2022 |
| Shades Tanning Studio Ltd | Other services | 2019 |
| Shadewell Installations Ltd | Construction | 2018 |
| Shadey Attachments Ltd | Manufacturing | 2020 |
| Shadin Bangla Limited | Hospitality | 2024 |
| Shadrock Advisory Ltd | Professional & scientific | 2025 |
| Shaftesbury International Services Ltd | Administrative & support | 1993 |
| Shah Canteen Ltd | Hospitality | 2025 |
| Shah Dermatology Ltd | Health & social care | 2023 |
| Shahi Grill and Pizza Ltd | Hospitality | 2026 |