An IMSI is usually presented as a 15-digit number but can be shorter. For example, MTN South Africa's old IMSIs that are still in use in the market are 14 digits long. The first 3 digits represent the mobile country code (MCC), which is followed by the mobile network code (MNC), either 2-digit (European standard) or 3-digit (North American standard). The length of the MNC depends on the value of the MCC, and it is recommended that the length is uniform within a MCC area. The remaining digits are the mobile subscription identification number (MSIN) within the network's customer base, usually 9 to 10 digits long, depending on the length of the MNC.