I have bought Norton 360 3 users licenses and I have two desk tops and 1 mobile (android ), but cannot install it in my mobile it said my license have expired.
For me, the easiest way to install on my PCs was to log in to My Norton Account and download Norton 360 from there. For the Androids, I downloaded Norton app from Google Play. You may have inadvertently be logged into a free 30 day Norton trial rather than your actual Norton 360 account.
If you have had 360 for more than 4 months, you are on the older 360 product that did not give coverage for mobile devices. If this is the case, you will need to upgrade your product to the newer Norton Security product line to be able to use Norton Mobile Security on a mobile device. Be aware that if you are using the backup feature of 360, you will need the Premium version, as that is the only version that supports backup.
You can contact Norton Support and ask them to help with the upgrade. www.norton.com/contactcs