There are several reasons why cell phone users may want to block unwanted text message interactions, and it's also useful to know how to unlock the blocking feature. While not all Sprint phone plans allow the users to lock and unlock text message features, the Premium Text Message service allows users to block and unblock text messages by going online and changing options in their Sprint account.
Sign into your sprint.com account.
Click on the "My device and media" tab near the top of the screen.
Select the "Messaging" icon from the list that appears.
Click the "Block texts" option.
Select the short code to be removed from the blocked list. Short codes are four- to six-digit codes that appear with the message, often from vendors or advertisers.
Click the "Remove from block list" option.
Users can also unblock a short code number by texting the word "Allow" followed by the phone number or the short code to the number "9999" or by calling Sprint customer service.