Delete Single Message
Step 1. Unlock your iPhone and go to the ‘Messages’ application. It should be on your taskbar by default.
Step 2. On the top left corner of the screen, you will see an ‘Edit’ button. Click on this button.
Step 3. Doing this will enable you to select the messages you want to delete. If you so wish, you can select multiple messages also.
Step 4. Complete your selection and click on the ‘Delete’ button at the bottom right side of the screen.
Step 5. Congratulations! The messages you selected have been deleted.
Delete All Messages
Step 1. Unlock your iPhone and go to your home page. Look for the ‘Settings’ application. It will be the app with a grey icon.
Step 2. Click on the icon to open ‘Settings’.
Step 3. On the ‘Settings’ page that opens, scroll down to ‘Messages’. You will find it in the fifth option segment. Click on the button to open messaging settings.
Step 4. On the new screen that appears, look for the ‘Message History’ section. Under the heading, you will see the option to ‘Keep messages’. By default, your phone saves all your text conversations forever, unless you manually delete them. Click on ‘Keep Messages’ to make changes to the settings.
Step 5. You will now be asked how long you want to keep your messages for. You can choose between ‘1 Year’ or ‘30 Days’. Select the option you want.
Step 6. Next, your iPhone will ask you for the confirmation that you want to delete all messages older than a month or a year, according to what you chose. To confirm your selection, click on ‘Delete’.
Step 7. Open the messages application once again. You will find that the messages older than the time period selected have been deleted. In case you find that a conversation you wanted gone; has not been deleted, you can manually delete it through the ‘Delete Single Message’ process. The process has now been completed.