Taiyuan Unicom has a mobile phone card with two numbers.

One-card dual-number service refers to configuring a number provided by a cooperative operator on the same SIM card. The corresponding MSSDN on the home network of the SIM card is called the primary number, and the number of the cooperative operator is the secondary number in the case of visit, and the MSSDN of China Unicom is called the primary number. China United Network Communications Group Co., Ltd., referred to as "China Unicom", was formed by the merger and reorganization of the former China Netcom and the former China Unicom on June 6, 2009.