| KIP Protocol Limited | | Live |
| PROTOCOL CENTURY LIMITED | Private company limited by shares | Dissolved |
| Protocol Direct Dialing Limited | Private company limited by shares | Dissolved |
| Duchamp Protocol Limited | Private company limited by shares | Live |
| ENTERPRISE PROTOCOL LIMITED | Private company limited by shares | Dissolved |
| First Protocol Limited | Private company limited by shares | Dissolved |
| GTGOLD PROTOCOL LIMITED | | Live |
| Elite Protocol Hong Kong Company Limited | Private company limited by shares | Live |
| Initial Assessment Protocol Limited | Private company limited by shares | Live |
| KONNECT PROTOCOL LIMITED | | Live |
| PROTOCOL RESEARCH LIMITED | Private company limited by shares | Live |
| PROTOCOL RESOURCES HK LIMITED | Private company limited by shares | Dissolved |
| SWAP PROTOCOL LIMITED | Private company limited by shares | Live |
| PROTOCOL VOIP LIMITED | Private company limited by shares | Dissolved |
| PROTOCOM CYBERTECH LIMITED | Private company limited by shares | Dissolved |
| PROTOCOM NETWORKS AND SYSTEMS LIMITED | Private company limited by shares | Live |
| PROTODEAL LIMITED | Private company limited by shares | Live |
| Protodype Limited | Private company limited by shares | Live |
| PROTOFUN HK CO., LIMITED | Private company limited by shares | Live |
| PROTOGENIA LIMITED | Private company limited by shares | Live |
| PROTOGON GLOBAL LIMITED | Private company limited by shares | Live |
| ProtoInfo Company Limited | Private company limited by shares | Live |
| PROTOLITE LIMITED | Private company limited by shares | Dissolved |
| PROTOM ASIA LIMITED | Private company limited by shares | Live |
| PROTOMAX LIMITED | Private company limited by shares | Dissolved |
| PROTON RAY LIMITED | Private company limited by shares | Dissolved |
| PROTON LIMITED | Private company limited by shares | Dissolved |
| PROTON HK LIMITED | Private company limited by shares | Dissolved |
| PROTON LED LIMITED | Private company limited by shares | Live |
| Proton Limited | Private company limited by shares | Live |
| Joy Proton Limited | Private company limited by shares | Live |
| Proton Capital Limited | Private company limited by shares | Live |
| Proton Capital HK Limited | Private company limited by shares | Dissolved |
| PROTON ENTERPRISES LIMITED | Private company limited by shares | Dissolved |
| PROTON INGREDIENTS LIMITED | Private company limited by shares | Dissolved |
| PROTON VIEW LIMITED | Private company limited by shares | Dissolved |
| PROTONBASE LIMITED | Private company limited by shares | Dissolved |
| Protonbase HK Limited | Private company limited by shares | Live |
| PRO-TONE LIMITED | Private company limited by shares | Dissolved |
| PROTONG LIMITED | Private company limited by shares | Dissolved |
| PROTONIC HOLDINGS LIMITED | Private company limited by shares | Live |
| Protonic Labs Limited | | Live |
| PROTONICS LIMITED | Private company limited by shares | Dissolved |
| Protons (Asia) Limited | Private company limited by shares | Live |
| PROTONTEK INTERNATIONAL LIMITED | Private company limited by shares | Live |
| PROTOOLDESIGN (HK) CO., LIMITED | Private company limited by shares | Live |
| PROTOOLDIE (HK) LIMITED | Private company limited by shares | Live |
| PRO-TOOLING LIMITED | Private company limited by shares | Dissolved |
| PROTOP COMPANY LIMITED | Private company limited by shares | Dissolved |
| PROTOP CORPORATION LIMITED | Private company limited by shares | Live |
| PROTOP GOLF CORPORATION LIMITED | Private company limited by shares | Dissolved |
| PROTOP TRADING DEVELOP LIMITED | Private company limited by shares | Live |
| PROTOP DEVELOPMENT LIMITED | Private company limited by shares | Live |
| PROTOP TECHNOLOGY (H.K.) LIMITED | Private company limited by shares | Dissolved |
| PROTOP HOLDING LIMITED | | Live |
| PROTOP IMPORT & EXPORT CO., LIMITED | Private company limited by shares | Dissolved |
| PROTOP INDUSTRIES CO., LIMITED | Private company limited by shares | Live |
| ProTop (International) Consulting Groups Limited | Private company limited by shares | Live |
| Protop International Group Co., Limited | Private company limited by shares | Live |
| PROTOP INVESTMENT LIMITED | Private company limited by shares | Live |
| PROTOP PHOTO-GRAPHIC-ARTS LIMITED | Private company limited by shares | Dissolved |
| Protop Financial Press Limited | Private company limited by shares | Live |
| PRO-TOP TECHNOLOGY LIMITED | Private company limited by shares | Dissolved |
| Pro-top Trading Co. Limited | Private company limited by shares | Live |
| Protopia International Company Limited | | Live |
| QINGDAO JINGNIANG PROTOPLASM BEER LIMITED | | Live |
| Protoporos Enterprises Limited | | Live |
| PROTORAY LIMITED | Private company limited by shares | Live |
| PROTOS LIMITED | Private company limited by shares | Dissolved |
| Protos Limited | Private company limited by shares | Live |
| Protos Limited | | Live |
| PROTOS DESIGN LIMITED | Private company limited by shares | Dissolved |
| Protoscapes Limited | Private company limited by shares | Live |
| Protoss Capital Limited | Private company limited by shares | Live |
| PROTOSTAR SOLUTION LIMITED | Private company limited by shares | Live |
| Protostar Tech Limited | Private company limited by shares | Live |
| PROTOTRONICS COMPANY LIMITED | Private company limited by shares | Dissolved |
| A PROTOTYPE COMPANY LIMITED | Private company limited by shares | Live |
| RP PROTOTYPE LIMITED | Private company limited by shares | Live |
| HSR Prototype Limited | Private company limited by shares | Live |
| MAX PROTOTYPE LIMITED | Private company limited by shares | Live |
| Prototype Limited | Private company limited by shares | Live |
| 3S Prototype Limited | | Live |
| AESTHETICS PROTOTYPE LIMITED | Private company limited by shares | Live |
| ANSON RAPID PROTOTYPE CO., LIMITED | Private company limited by shares | Live |
| MXP Prototype Co., Limited | | Live |
| APA PROTOTYPE CO., LIMITED | | Live |
| Brightstar prototype CNC Co., Limited | | Live |
| HK LT CENTURY PROTOTYPE CO., LIMITED | Private company limited by shares | Live |
| LT CENTURY PROTOTYPE CO., LIMITED | Private company limited by shares | Live |
| DADESIN PROTOTYPE CO., LIMITED | Private company limited by shares | Live |
| Faster Prototype Co., Limited | Private company limited by shares | Dissolved |
| Looker Prototype Co., Limited | Private company limited by shares | Dissolved |
| SG PROTOTYPE MANUFACTURER CO., LIMITED | Private company limited by shares | Live |
| JG Prototype Manufacturer Co., Limited | Private company limited by shares | Live |
| Ivy Prototype Manufacturing Co., Limited | Private company limited by shares | Live |
| A Prototype Manufacturing Co., Limited | Private company limited by shares | Live |
| LK Prototype Molding Co., Limited | Private company limited by shares | Live |
| XSHENG PROTOTYPE CO., LIMITED | Private company limited by shares | Live |
| TEAM CREATION PROTOTYPE & DESIGN LIMITED | Private company limited by shares | Dissolved |