The present specification relates to a portable device, a smart watch, which is used in a manner of being synchronized with the portable device, and a method of controlling therefor. According to one embodiment, the processor configured to detect a first external device including a second ID, if the second ID of the first external device is identical to the first ID of the portable device, the processor configured to include the first ID of the portable device in ID information, if the second ID of the first external device is different from the first ID of the portable device, the processor configured to include the second ID of the first external device in the ID information, the processor configured to transmit the data including the ID information to a second external device.