| 999 DR. HEALTH SERIES (SED) LIMITED | Private company limited by shares | Dissolved |
| SILVER SERIES LIMITED | Private company limited by shares | Dissolved |
| SMART 2023 Series A Limited | | Live |
| Soul Series Limited | Private company limited by shares | Live |
| SPECIAL SERIES LIMITED | Private company limited by shares | Live |
| Spot Series (Moon) Asia Company Limited | | Live |
| Spot Series (Ocean) Asia Company Limited | | Live |
| Spot Series (Sun) Asia Company Limited | | Live |
| Time Series Limited | | Live |
| Sun Series Travel Company Limited | Private company limited by shares | Live |
| Tsang's Series Limited | Private company limited by shares | Live |
| 999 DR. HEALTH SERIES (YLD) LIMITED | Private company limited by shares | Dissolved |
| Sans Serif Limited | Private company limited by shares | Live |
| SERIGHT COMPANY LIMITED | Private company limited by shares | Dissolved |
| SERIKA LIMITED | Private company limited by shares | Live |
| LA SERIKA IMMOBILIARE LIMITED | Private company limited by shares | Dissolved |
| SERIKA (HONGKONG) TRADING CO., LIMITED | Private company limited by shares | Live |
| SERIKAN LIMITED | Private company limited by shares | Dissolved |
| SERIKONG COMPANY LIMITED | Private company limited by shares | Live |
| SERILAND INTERNATIONAL TRADING CO., LIMITED | Private company limited by shares | Dissolved |
| SERIN LIMITED | Private company limited by shares | Live |
| SERIN ENTERPRISES LIMITED | Private company limited by shares | Live |
| SERIN INVESTMENT LIMITED | Private company limited by shares | Dissolved |
| SERINA CO., LIMITED | Private company limited by shares | Dissolved |
| SERINA EURO-CHINA COMMERCIAL & INDUSTRIAL SERVICE LIMITED | Private company limited by shares | Dissolved |
| SERINDIA LIMITED | Private company limited by shares | Live Commenced dormancy on 27-Apr-2009 |
| ART SERINDIA LIMITED | Private company limited by shares | Live |
| Sering Company Limited | Private company limited by shares | Live |
| SERING INVESTMENTS LIMITED | Private company limited by shares | Live |
| Serino Limited | Private company limited by shares | Live |
| SERINUS LIMITED | Private company limited by shares | Dissolved |
| SERIO COMPANY LIMITED | | Live |
| Serio Asia Investment Limited | Private company limited by shares | Live |
| SERIO SALES LIMITED | Private company limited by shares | Dissolved |
| SERIONA GROUP LIMITED | Private company limited by shares | Live Commenced dormancy on 21-Jun-2016 |
| SERIOUS EXHIBITION CONSULTANT CO., LIMITED | Private company limited by shares | Dissolved |
| SERIOUS MARKETING COMMUNICATIONS (HK) LIMITED | Private company limited by shares | Live |
| Serious Enterprise Management Consulting (HK) Limited | Private company limited by shares | Live |
| Serious Employment Centre Limited | Private company limited by shares | Live |
| SERIOUS LANDSCAPING & ENGINEERING LIMITED | Private company limited by shares | Live |
| SERIOUS ENTERTAINMENT LIMITED | | Live |
| SERIOUS FASHION CO., LIMITED | Private company limited by shares | Live |
| SERIOUS FISH LIMITED | Private company limited by shares | Live |
| SERIOUS GROUP COMPANY LIMITED | Private company limited by shares | Live |
| SERIOUS INTERNATIONAL LIMITED | Private company limited by shares | Live |
| SERIOUS MARKETING LIMITED | Private company limited by shares | Live |
| SERIOUS MODE LIMITED | | Live |
| Serious Monkey Limited | Private company limited by shares | Live |
| Y Show Serious Limited | Private company limited by shares | Live |
| SERIOUS SPACE LIMITED | Private company limited by shares | Live |
| SERIOUS STAGING LIMITED | Private company limited by shares | Live |
| Serious Tech Limited | Private company limited by shares | Live |
| FRICK SERIOUS ELECTRONIC TECHNOLOGY (H.K.) CO. LIMITED | Private company limited by shares | Dissolved |
| Serious Learning Tool Limited | Private company limited by shares | Live |
| Why So Serious Training Limited | Private company limited by shares | Live |
| Serious Tubes Limited | Private company limited by shares | Live |
| WINE SO SERIOUS LIMITED | Private company limited by shares | Live |
| SERIOUSLEE 41 LIMITED | | Live |
| SERIOUSLEE 42 LIMITED | | Live |
| SERIOUSLEE 43 LIMITED | | Live |
| SERIOUSLEE 44 LIMITED | | Live |
| SERIOUSLEE 45 LIMITED | | Live |
| SERIOUSLY ROMANTIC HK LIMITED | Private company limited by shares | Live |
| SERIPRINCE Limited | Private company limited by shares | Live |
| Seristine Properties Limited | Private company limited by shares | Live |
| SERISYS GROUP LIMITED | Private company limited by shares | Live |
| SERISYS SOLUTIONS LIMITED | Private company limited by shares | Live |
| Seritec Limited | Private company limited by shares | Dissolved |
| SERIUS DIAMONDS CO., (H.K.) LIMITED | Private company limited by shares | Dissolved |
| HANGJING MARINE SERIVCE CO., LIMITED | | Live |
| Han&Lu Consulting Serivce Co., Limited | | Live |
| Exuberant International Travel Serivice Limited | Private company limited by shares | Live |