How to Back up iPhone Textsby Spanner Spencer ; Updated September 28, 2017
The iPhone backs up the majority of its content every time it synchronizes with iTunes. Apple's desktop software doesn't allow users to manually restore individual aspects of these backups, such as SMS text messages or the address book. A full iPhone restore is the only way to retrieve data for a specific application. By locating the exact backup file on the computer, SMS text messages can be manually backed up and restored as required.
Connect the iPhone to the computer using the USB cable, and click the "Sync" button in iTunes to perform a full synchronization and backup.
Close iTunes, and click the "Start" button on the computer, followed by "Search."
Perform a computer-wide search for the following file: "3d0d7e5fb2ce288813306e4d4636395e047a3d28" This is the SMS text message part of the iPhone's backup package.
Copy the text message backup file to another location on the computer, or upload it to any online backup storage systems you have access to. This file can now be used as a backup of all text messages received by the iPhone prior to the synchronization performed in Step 1.
Online services are available that can convert the iTunes backup file into a text file, spreadsheet, or other readable file formats. Restore the text message data manually by replacing the existing iTunes file with the your backup version. The same operation can be carried out for the iPhone's address book by locating the file "31bb7ba8914766d4ba40d6dfb6113c8b614be442."