| SUMMA ECI LIMITED | Private company limited by shares | Dissolved |
| SUMMA LIMITED | Private company limited by shares | Dissolved |
| Summa Company Limited | Private company limited by shares | Live |
| SUMMA CAPITAL LIMITED | Private company limited by shares | Dissolved |
| SUMMA ENTERPRISES LIMITED | Private company limited by shares | Dissolved |
| SUMMAGRAPHICS FAR EAST LIMITED | Private company limited by shares | Dissolved |
| Summan Company Limited | Private company limited by shares | Live |
| SUMMAN BASKETBALL COMPANY LIMITED | Private company limited by shares | Live |
| SUMMAN ENGINEERING LIMITED | Private company limited by shares | Live |
| SUMMANA COMPANY LIMITED | Private company limited by shares | Dissolved |
| Summanus Limited | | Live |
| Summarize Limited | Private company limited by shares | Live |
| Summary Limited | Private company limited by shares | Live |
| SUMMATICS LIMITED | Private company limited by shares | Live |
| Summation Group Limited | Private company limited by shares | Live |
| SUMMATION X HOLDINGS LIMITED | Private company limited by shares | Dissolved |
| Summation FinTech (Hong Kong) Limited | Private company limited by shares | Live |
| SUMMATION INTERNATIONAL HOLDINGS LIMITED | Private company limited by shares | Live |
| SUMMATION OFFICE SYSTEMS CO. LIMITED | Private company limited by shares | Dissolved |
| Summau Investment Co., Limited | | Live |
| SUMMAX COMPANY LIMITED | Private company limited by shares | Live |