| UNITED DIGITAL SOLUTIONS COMPANY LIMITED | Private company limited by shares | Dissolved |
| UNION TONE INVESTMENT DEVELOPMENT LIMITED | Private company limited by shares | Live |
| UNIWELL INDUSTRY (HK) LIMITED | Private company limited by shares | Dissolved |
| UNION METAL COOPERATION LIMITED | Private company limited by shares | Live |
| UNITEAM ENGINEERING LIMITED | Private company limited by shares | Live |
| UGRAND UNIVERSAL LIMITED | Private company limited by shares | Live |
| KILO UNIVERSAL LIMITED | Private company limited by shares | Live |
| METRO UNION DEVELOPMENT LIMITED | Private company limited by shares | Dissolved |
| TRADING UNION LIMITED | Private company limited by shares | Dissolved |
| UNION RISING LIMITED | Private company limited by shares | Live |
| UNION EXPO LIMITED | Private company limited by shares | Dissolved |
| ADVANCE UNION LIMITED | Private company limited by shares | Dissolved |
| UNI-FAMOUS LIMITED | Private company limited by shares | Dissolved |
| UNIVERSAL POWER LIMITED | Private company limited by shares | Dissolved |
| UNIQUE BUSINESS LIMITED | Private company limited by shares | Live |
| UNIQUE WEALTH LIMITED | Private company limited by shares | Live |
| CHINESE ONLINE ANTI-PIRACY UNION LIMITED | Private company limited by shares | Dissolved |
| UCHIYAMA GLOBAL UNDERWRITING CO., LIMITED | Private company limited by shares | Dissolved |
| WEALTHY UNION DEVELOPMENT LIMITED | Private company limited by shares | Live |
| UNIVERSAL MATE ENTERPRISE LIMITED | Private company limited by shares | Dissolved |
| Hong Kong Union Business Service Limited | Private company limited by shares | Live |
| FULL UNIVERSE LIMITED | Private company limited by shares | Dissolved |
| UNION CREATION INVESTMENTS LIMITED | Private company limited by shares | Live |
| UNION CARGO INTERNATIONAL FORWARDER CO., LIMITED | Private company limited by shares | Live |
| DJL UNITED LIMITED | Private company limited by shares | Live |
| UNION CONCEPT INDUSTRIAL LIMITED | Private company limited by shares | Live |
| METRO UNION LIMITED | Private company limited by shares | Dissolved |
| UNIVERSE RESOURCE INDUSTRY LIMITED | Private company limited by shares | Dissolved |
| UNION PROFIT ENTERPRISES LIMITED | Private company limited by shares | Dissolved |
| UNION TEAM INVESTMENT LIMITED | Private company limited by shares | Live |
| UNION SCORE HOLDINGS LIMITED | Private company limited by shares | Live |
| UNION SENSE INDUSTRIES LIMITED | Private company limited by shares | Live |
| UNION CENTURY TRADING LIMITED | Private company limited by shares | Live |
| Unison Hong Kong Engineering Company Limited | Private company limited by shares | Live |
| UNIS INTERNATIONAL LIMITED | Private company limited by shares | Dissolved |
| CHINA UNISON HOLDINGS LIMITED | Private company limited by shares | Live |
| UNICOBA INTERNATIONAL LIMITED | Private company limited by shares | Dissolved |
| UNITEK SOLUTIONS LIMITED | Private company limited by shares | Dissolved |
| Union Technology Development Co., Limited | Private company limited by shares | Dissolved |
| UNION TEAM (H.K.) LIMITED | Private company limited by shares | Live |
| UNIMAX ENTERPRISE LIMITED | Private company limited by shares | Live |
| UNION WATER HOLDING CO., LIMITED | Private company limited by shares | Dissolved |
| TRIPLE UNION DEVELOPMENT LIMITED | Private company limited by shares | Dissolved |
| FOREVER UNION INTERNATIONAL CO., LIMITED | Private company limited by shares | Live |
| CELSIUS UNIVERSE COMPANY LIMITED | Private company limited by shares | Live |
| U.S.A UNION GROUP (CHINA) INVESTMENT LIMITED | Private company limited by shares | Live |
| UNION HONEST PROPERTIES AGENCY LIMITED | Private company limited by shares | Live |
| UNI-BRIGHT CREATION LIMITED | Private company limited by shares | Dissolved |
| CHINA UNICHEM LIMITED | Private company limited by shares | Live |
| South Union Holding Limited | Private company limited by shares | Live |
| DLM UNIVERSAL LIMITED | Private company limited by shares | Dissolved |
| UNION KING INTERNATIONAL (H.K.) DEVELOPMENT LIMITED | Private company limited by shares | Live |
| WIN UNION LIMITED | Private company limited by shares | Dissolved |
| UNION GLOBAL DEVELOPMENT LIMITED | Private company limited by shares | Dissolved |
| EVER UNION LIMITED | Private company limited by shares | Dissolved |
| South Union Corporation Limited | Private company limited by shares | Live |
| South Union International (HK) Limited | Private company limited by shares | Live |
| UNITED RICHEST LIMITED | Private company limited by shares | Live |
| UNION LINKER INDUSTRIAL LIMITED | Private company limited by shares | Live |
| UNICHEM (CHINA) LIMITED | Private company limited by shares | Live |
| JAMAY KNITTING UNDERWEAR LIMITED | Private company limited by shares | Live |
| UNITED GROWTH LIMITED | Private company limited by shares | Live |
| SINO-US UNION TRADE GROUP CO., LIMITED | Private company limited by shares | Dissolved |
| UNI-LITE TECHNOLOGY (HK) LIMITED | Private company limited by shares | Live Commenced dormancy on 07-Jun-2016 |
| H.K.ANQI UNIVERSAL GROUP LIMITED | Private company limited by shares | Dissolved |
| UNI-FAITH LIMITED | Private company limited by shares | Live |
| UNITED WORLD CHINESE WATER SUPPLIES INVESTMENT (HOLDINGS) COMPANY LIMITED | Private company limited by shares | Dissolved |
| UNITCOM LIMITED | Private company limited by shares | Dissolved |
| UNIRISX HK Limited | Private company limited by shares | Live |
| UNION PRODUCTIONS LIMITED | Private company limited by shares | Live |
| CROWN UNION TRADING LIMITED | Private company limited by shares | Dissolved |
| UNITED WAY SHIPPING LIMITED | Private company limited by shares | Live |
| HONGKONG LEFIE UNION CO., LIMITED | Private company limited by shares | Live |
| ALL UNISON HONGKONG LIMITED | Private company limited by shares | Live |
| UNIVERSAL BUSINESS FURNITURE LIMITED | Private company limited by shares | Dissolved |
| KINDLY UNION CO., LIMITED | Private company limited by shares | Dissolved |
| UNICOM INVESTIGATION LIMITED | Private company limited by shares | Dissolved |
| UNION LEADER (HONG KONG) LIMITED | Private company limited by shares | Live |
| GOLD UNITED TECHNOLOGY LIMITED | Private company limited by shares | Live |
| UNION BROADBAND TELECOMMUNICATION GROUP LIMITED | Private company limited by shares | Dissolved |
| UNION EVER INVESTMENTS LIMITED | Private company limited by shares | Live |
| UNION HONEST DEVELOPMENT LIMITED | Private company limited by shares | Live |
| HONGKONG UNION CREDIT MANAGEMENT CORPORATION LIMITED | Private company limited by shares | Dissolved |
| ASIAN RUGBY FOOTBALL UNION LIMITED | Company limited by guarantee | Live |
| LUCKY UNION TRADING LIMITED | Private company limited by shares | Live |
| TRANS UNION EXPRESS LIMITED | Private company limited by shares | Live |
| YEE SHING (UNION) ENGINEERING COMPANY LIMITED | Private company limited by shares | Live |
| Universal Fly Tech Limited | Private company limited by shares | Live |
| RIGHT UNION INTERNATIONAL DEVELOPMENT LIMITED | Private company limited by shares | Live |
| UNIVERSE DOOR FACTORY COMPANY LIMITED | Private company limited by shares | Dissolved |
| UNITED PUBLIC OILFIELD SERVICE LIMITED | Private company limited by shares | Live |
| CHINA ANIMATION COMMERCE INTERACTIVE UNION LIMITED | Private company limited by shares | Dissolved |
| UNION TARGET INVESTMENTS LIMITED | Private company limited by shares | Dissolved |
| UNION FOOD STUFF (INTERNATIONAL) COMPANY LIMITED | Private company limited by shares | Live |
| MEGA UNION HONG KONG INVESTMENT LIMITED | Private company limited by shares | Dissolved |
| UNION LINK ASIA GROUP LIMITED | Private company limited by shares | Live |
| FRIEND UNION LIMITED | Private company limited by shares | Live |
| UNSION COMPANY LIMITED | Private company limited by shares | Dissolved |
| UNIVERSAL C & D CO., LIMITED | Private company limited by shares | Live |
| UNION TRADE CORPORATION LIMITED | Private company limited by shares | Live |