Union Commercial Bank Plc (UCB) was founded by Oknha Yum Sui Sang and several investors on 31st March 1994. After 20 years of efforts, UCB has established itself as a well-known financial institution in Cambodia. In September 2013, E.SUN Bank in Taiwan invested 70% shares of UCB, and acquired additional 5% in 2015. It was owned by E.SUN Bank 100% in March 2017.