Use identifierForVendor, this unique string is same till you not delete your application from the device. Swift : var uniqueId = UIDevice . currentDevice (). identifierForVendor . UUIDString println ( "identifierForVendor : \ (uniqueId)" ) Objective-C : NSString * uniqueId = [[[UIDevice currentDevice] identifierForVendor] UUIDString]; Refrence Link : http://possiblemobile.com/2013/04/unique-identifiers/