To block your phone number while texting, use email to send your text or use a number-changing app on a smartphone. If you use email, make sure the account you send the text from is not connected to any other accounts that might reveal your identity, such as Facebook or Gmail.
To send an anonymous text using the email method, you must know the recipient's carrier. For AT&T users, enter the recipient's 10-digit number followed by "@txt.att.net." For Verizon Wireless, enter the number followed by "@vtext.com." For Sprint, use the number followed by "@messaging.sprintpcs.com." For T-Mobile, input the phone number followed by "@tmomail.net."
If you have a smartphone, download the Anonymous Texting or Anonytext apps for Android. For iOS users, install the Pinger or TextPlus apps, which change your number to something else for anonymity.