In case someone is still interested in knowing the answer, for API >= 22 only
// you may ignore TelephonyManager if you don't want to get the IMEI
TelephonyManager telephonyManager = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
SubscriptionManager subscriptionManager = SubscriptionManager.from(getApplicationContext());
List<SubscriptionInfo> subsList = subscriptionManager.getActiveSubscriptionInfoList();
for (SubscriptionInfo subscriptionInfo : subsList ) {
// get IMEI
int simSlotIndex = subscriptionInfo.getSimSlotIndex();
String imei = telephonyManager.getImei(simSlotIndex);
// get serial number
String serialNumber = subscriptionInfo.getIccId();
// get line number
String lineNumber = subscriptionInfo.getNumber();
}