In order to block someone from texting, the person who wishes to block the other person must contact their phone service providers. Phone service providers are the only ones who can block phone calls and text messages from known numbers.
Unfortunately, if the annoying text or harassment text is coming from an unknown or anonymous number, then the service provider will not be able to block the messages or calls. The amount of numbers that can be blocked depends on the phone service provider; Verizon currently allows five numbers to be blocked for free while AT&T currently allows 30 numbers to be blocked for a paid Smart Line service. Verizon limits the block to 90 days, but allows users to reblock the numbers after each 90-day period. Verizon also offers a paid service that allows 20 numbers to be blocked without a time limit.
Unwanted texts often come as a form of textual harassment. This problem is often present with young people and is a form of cyber bullying. Parents are encouraged to ask their children and teens to speak up if there is any form of harassment going on through text messages. Children and teens may be hesitant to speak about cyber bullying and textual harassment so it is important to make them feel comfortable with sharing.