There are multiple ways to send private text messages on a cellphone, including using email, instant messaging and certain smartphone apps. To maintain complete anonymity, the user should create a unique email address or instant messaging account depending on how he chooses to privately text an individual.
The first way to send private text messages is to use email. The user must use the following templates dependant on the recipient's cell phone carrier. For AT&T users, he can send simple messages to the ten digit phone number (written as one long word with no spaces or hyphens) followed by @txt.att.net. For Verizon, he must email the number followed by @@vtext.com, paying attention to use double @ symbols. For Sprint, they must email the number followed by @messaging.sprintpcs.com and for T-Mobile, the number followed by @tmomail.net. For Metro PCS, he must use the number followed by @mymetropcs.com.
For users who use instant messaging software such as iChat and AIM, private texts can be sent by clicking on File and then Send SMS. Afterward, they simply enter the number and text.
Finally, certain Android smartphone apps can be used to text privately, including the apps named Anonytext and Anonymous Texting. As of 2013, the iPhone does not have any specific apps to send fully private text messages.