By default, the iPhone keeps all messages forever (or until you manually delete them). If you prefer, tap “30 Days” or ‘1 Year.” If you do, the iPhone will automatically discard your messages after the selected time period.
Do iPhone messages ever disappear?
When a text message is deleted on the iPhone, it doesn’t disappear permanently. First, a copy of it is sent to the network provider. Next, the copy in your phone isn’t permanently deleted, but rather marked as “deleted” by the iPhone’s internal database.
How long do text messages stay on your phone?
Most newer Android devices will let you view all your text messages but older models may limit you to viewing just the last 30 days’ worth of messages. In some instances, you can delete messages as old as 3 months. In some other carriers, you can go beyond 6 months.