Hello, dear, I'm glad to serve you, for the following reasons: 1, the mobile phone has interception software. Unable to receive verification code. I suggest you check it out. Remove SMS blocking of application software. 2. There is no signal on the mobile phone. Or there will be arrears, downtime and so on. I hope you can adjust carefully and pay the phone bill in time if you owe money. Return to normal signal 3. The mobile phone is disturbed or out of service area. Unable to receive verification code. In this case, you must go to the area with signal in time. 4. The chief SMS is stored too much. It takes up too much space. Information is not easy to input. I hope to clean it up in time. Will get good results.