| HK SERMA ELECTRONICS LIMITED | Private company limited by shares | Dissolved |
| SERMA INTERNATIONAL COMPANY LIMITED | Private company limited by shares | Live |
| SERMAN LIMITED | Private company limited by shares | Live |
| SERMAN INVESTMENT LIMITED | Private company limited by shares | Dissolved |
| SERMAR CO., LIMITED | Private company limited by shares | Live |
| SERMART INDUSTRIAL LIMITED | Private company limited by shares | Live |
| SERMATA COMPANY LIMITED | Private company limited by shares | Dissolved |
| SERMAX LIMITED | Private company limited by shares | Dissolved |
| SERMAX INVESTMENTS LIMITED | Private company limited by shares | Dissolved |
| Sermen Asia Limited | Private company limited by shares | Live |
| Sermer Company Limited | Private company limited by shares | Live |
| SERMON COMPANY LIMITED | Private company limited by shares | Live |
| SERMOST LIMITED | Private company limited by shares | Dissolved |
| SERMUK LIMITED | | Live |