How to Mark a Text as Unread on iPhone
Starting in iOS 16 (and in iPadOS 16 on the iPad), you can mark text messages as unread in the pre-installed Messages texting app (you can also pin conversations to the top of the window and mute notifications for them). If you’re running an earlier version of iOS on your iPhone, you don’t have this feature and this is one of many good reasons to upgrade your OS.
Unread Text Messages and Read Receipts
Some Messages users have enabled Read Receipts, a feature that lets the person who they’re texting with know when they’ve read the text the other person has sent. Marking a text as unread using these instructions doesn’t change the status of a Read Receipt. If you have read a text and a Read Receipt has been sent (you’ll see the status just below the latest text within the conversation), marking the text doesn’t change what the person you’re talking to sees. They still get the Read Receipt. Marking as unread only changes the status of the message on your iPhone.
How to Filter Messages to Show Only Unread Texts on iPhone
If you only want to see unread texts, here’s the setting to change: