How to find out who is sending harassing text messages?

You can charge some phone bills to his mobile phone number, and his information is on the phone bill.

If you don't want to spend money, aren't you a suspect You can pretend to charge the phone bill, quote the name you suspect and ask if it is the owner. If not, you can say the number is wrong and leave.

Hehe, I wish you find this hateful person ~