| Seedat Bathrooms Ltd | Wholesale & retail | 2025 |
| Seedat Carpet & Flooring Fitting Services Ltd | Construction | 2017 |
| Seedat Distribution Ltd | Construction | 2025 |
| Seedat Optical Ltd | Health & social care | 2023 |
| Seedling Gifts Ltd | Wholesale & retail | 2017 |
| Seedprint Limited | Administrative & support | 2021 |
| Seehra Builders & Plumbers Merchants Limited | Wholesale & retail | 2013 |
| Seekcard Limited | Wholesale & retail | 2000 |
| Seelan Estates Limited | Real estate | 2025 |
| Seem Solutions Ltd | Information & communication | 2017 |
| Seema.Mistry Ltd | Real estate | 2026 |
| Seen Heard Theatre CIC | Arts & recreation | 2025 |
| Seerah Academy (Radio Seerah) | Education | 2014 |
| Seetara Ltd | Professional & scientific | 2025 |
| Sega Haulage Ltd | Transport & logistics | 2024 |
| Segam Import and Export Ltd | Wholesale & retail | 2024 |
| Segatomo UK Ltd | Health & social care | 2026 |
| Segment Intelligence Ltd | Information & communication | 2026 |
| Segrem Healthcare Services Ltd | Other services | 2024 |
| Sehaj & Tegh Singh Ltd | Real estate | 2025 |
| Sehaj Real Estate Ltd | Real estate | 2021 |
| Sehari Constructions Ltd | Construction | 2023 |
| Seicho Developments Limited | Wholesale & retail | 2024 |
| Seifein Solutions Limited | Real estate | 2022 |
| Seiko Global Limited | Administrative & support | 2025 |
| Seikocity Ltd | Wholesale & retail | 2025 |
| Seisin Ltd | Information & communication | 2007 |
| SEK Commerce Ltd | Wholesale & retail | 2025 |
| SEK Trading Limited | Wholesale & retail | 2016 |
| Sekhon & Advani Holdings Ltd | Real estate | 2019 |
| Sekhon Holdings Limited | Real estate | 2023 |
| Sekinah Olatunji Ltd | Wholesale & retail | 2025 |
| Sekond Chance Ltd | Information & communication | 2022 |
| Sekura Limited | Wholesale & retail | 2025 |
| SEL SPV Limited | Financial services | 2023 |
| Select & Bargain Ltd | Wholesale & retail | 2018 |
| Select a Car Midlands Limited | Wholesale & retail | 2018 |
| Select Car Shop Limited | Wholesale & retail | 2021 |
| Select Care Services Limited | Administrative & support | 2009 |
| Select Homes (Midlands) Limited | Construction | 2002 |
| Select Investments Ltd | Financial services | 2016 |
| Selective Marketplace Limited | Wholesale & retail | 1981 |
| Selena & Sophia Ltd | Wholesale & retail | 2015 |
| Self Health Resource Centre Limited | Wholesale & retail | 2008 |
| Self Reliance Ltd | Mining & quarrying | 2021 |
| Selfless Trade Ltd | Wholesale & retail | 2024 |
| Selfserve Storage Ltd | Transport & logistics | 2024 |
| Selina Bar and Restaurant Ltd | Hospitality | 2025 |
| Selkie Design Ltd | Information & communication | 2025 |
| Sell Family Properties Limited | Real estate | 2018 |
| Sellazon Limited | Wholesale & retail | 2020 |
| Sellazon Retail Ltd | Wholesale & retail | 2023 |
| Sellcell.Info Ltd | Wholesale & retail | 2014 |
| Selles Limited | Administrative & support | 2008 |
| Sellington Solutions Limited | Construction | 2020 |
| Selltogether Limited | Construction | 2025 |
| Sels and Vims Ltd | Health & social care | 2022 |
| Selston Property and Investments Limited | Financial services | 2020 |
| Selvi Business Consultancy Ltd | Professional & scientific | 2019 |
| SEM Pharma Limited | Extraterritorial | 2016 |
| SEM Tax Limited | Professional & scientific | 2014 |
| Semefab Holdings Limited | Professional & scientific | 2008 |
| Semenyih Tech Ltd | Information & communication | 2026 |
| Semper FI Management Ltd | Professional & scientific | 2020 |
| Semper Ultra Ltd | Information & communication | 2022 |
| Sempervox Limited | Professional & scientific | 2008 |
| Semuh Ltd | Construction | 2025 |
| SEN Chandra Ltd | Health & social care | 2024 |
| Sena Designs Ltd | Administrative & support | 2017 |
| Sena Inc Ltd | Real estate | 2019 |
| SEND2CHINA Logistics Ltd | Transport & logistics | 2024 |
| SENDY2511021 Ltd. | Transport & logistics | 2017 |
| Senga Bay Ltd | Wholesale & retail | 2018 |
| Sengh Ltd | Information & communication | 2024 |
| Senior Education Management Services Ltd | Education | 2017 |
| Senior Help Leicester Ltd | Administrative & support | 2019 |
| Senior Vape Limited | Other services | 2014 |
| Sennore Ltd | Wholesale & retail | 2025 |
| Senpire Trading Limited | Wholesale & retail | 2025 |
| Sensational-Haven Properties Ltd | Real estate | 2024 |
| Senshi Ltd | Wholesale & retail | 2024 |
| Senshollak International Limited | Health & social care | 2015 |
| Sensible Computing Solutions Limited | Information & communication | 1994 |
| Sensitive Care Solutions Ltd | Health & social care | 2016 |
| Sensoria Group Limited | Financial services | 2020 |
| Sentinal Building Ltd | Manufacturing | 2024 |
| Sentinal Consulting Ltd | Administrative & support | 2024 |
| Sentinal Investments Ltd | Real estate | 2024 |
| Sentinel Check Ltd | Information & communication | 2026 |
| Sentioapothecary Ltd | Manufacturing | 2024 |
| Sentiora Consulting Ltd | Information & communication | 2025 |
| Sentle Limited | Information & communication | 2016 |
| Senyaku Medical Limited | Health & social care | 2025 |
| Senzai Ltd | Wholesale & retail | 2021 |
| Senzo Style Ltd | Wholesale & retail | 2021 |
| Seoul Avenue Limited | Wholesale & retail | 2023 |
| Seoul Bowl Manchester Ltd | Hospitality | 2021 |
| Sepautumn Ltd | Health & social care | 2024 |
| Seph & Sears Ltd | Hospitality | 2025 |
| Sephton Risk Management Limited | Professional & scientific | 2020 |