Already have Key Premium on my PC.Do I need to buy a new subscription for my iphone? Does it make any diff if I use sync code from PC to phone or vice-versa? Thanks. (I'm a real beginner!)
No, you don't have to buy a new subscription for the iPhone since you already have a KEY premium on your PC. Please refer to this article to know how to sync your password data from the premium device to your other devices.
You can find more articles about the benefits of KEY sync here and about KEY premium here.