If your Instagram account is
set to public, anyone can see the photo or video, and the person you tagged will get a notification. If your Instagram account is private, only your approved followers can see the photo or video, and the person you tag will only get a notification if they're following you. You can choose to
make your account private at any time.
Note: If you're not able to tag someone, they may have changed
who can tag them in their privacy settings. You'll also be able to see if they don't allow tags.