国际移动设备识别码（International Mobile Equipment Identity，IMEI），即通常所说的手机串行号、手机“串号”，用于在移动电话网络中识别每一部独立的手机等移动通信设备，相当于移动电话的身份证。串行号共有15位数字，前6位（TAC）是型号核准号码，代表手机类型。接着2位（FAC）是最后装配号，代表产地。后6位（SNR）是串号，代表生产顺序号。最后1位（SP）一般为0，是检验码，备用。国际移动设备识别码一般贴于机身背面与外包装上，同时也存在于手机内存中，通过输入*#06#即可查找。

The International Mobile Station Equipment Identity or IMEI /aɪˈmiː/ is a number, usually unique, to identify 3GPP (i.e., GSM, UMTS and LTE) and iDEN mobile phones, as well as some satellite phones. It is usually found printed inside the battery compartment of the phone, but can also be displayed on-screen on most phones by entering *#06# on the dialpad, or alongside other system information in the settings menu on smartphone operating systems.