Unwanted text messages are not just a hassle, they can also be dangerous. In September 2012, CNet reported a rash of phishing using text messages on mobile phones, luring people into providing confidential information like passwords and account numbers to unscrupulous hackers. Even harmless text messages can cost you money if you pay for each text received on your phone. Your options for blocking text messages vary depending on who your service provider is. There are two ways of sending a text message to a cell phone: through email or from another cell phone. Spammers often use mass emails to send text messages to cell phones.
1AT&T:AT&T gives you the option to block unwanted text messages by blocking the sender's email address or the Internet domain. To access this feature, you can log into your AT&T account online and create a Message Preferences account. You can then block lists online or simply reply to unwanted texts with "BLOCK" written in the message. To block phone numbers from sending you text or calling you, you will have to purchase AT&T Smart Limits and register your account. You can then specify online the phone numbers you want blocked.
2Sprint: Blocking unwanted text messages from a Sprint phone is simply a matter of sending a text message to "9999" from your phone with the word "block" followed by the number or email address. For example, to block the number 555-123-1234, you would send the text message "block 5551231234" to 9999. You can also use this service to unblock numbers or email addresses. To do this, use the "allow" command instead of "block." For a full list of available commands, send "help" as a text message to 9999.
3T-Mobile: At the time of publication, T-Mobile does not offer a method for blocking text messages from specific numbers. If you don't use text messaging, you have the option to block all text messages from being sent to or from your phone. To disable text messaging, log in to your account and go to the Plans and Services section of the Manage page. T-Mobile encourages customers to report spam text messages by forwarding them to "SPAM" (7726). This helps T-Mobile to identify and block spammers from T-Mobile services.
4Verizon:To block unwanted text messages from a Verizon phone, log in to your My Verizon account on your computer, smartphone or at a Verizon Wireless Store kiosk. An option to "Block Calls & Messages" is located under the Plan options on your account page. This gives you two options. You can list up to 15 email address or domains, which will then be unable to send you text messages in the future. Your second choice is to select the "Block All Internet Spam" option, blocking all messages except those sent from your friends' phones.