In some cases, a mobile device left on, but not used, may incur charges. If a voice call is received but not answered, and the caller leaves a voicemail, you may receive a charge for the voice call. If a text message comes through and the mobile device is left on, you may be charged for a received text message. Please note that devices (iOS, Android, and others) are constantly looking for data connections to perform updates and other synchronization steps. Therefore, it is highly possible that if you leave your wireless device on, you will incur data charges. Please contact your carrier for more information on charges.