Paying annually requires an up-front payment for a fixed number of devices. By subscribing annually rather than monthly you save 15%. This plan is primarily designed for customers who wish to pay once and not deal with monthly automatic payments. It also makes most sense if your device count will not be changing frequently. However it is possible to subscribe annually and extend your subscription as and when you add more devices. To extend your subscription go to "My Account" > Extend Subscription.
Your subscription is 2 months into a 12 month subscription.
You originally paid for 10 devices.
You have added an extra 5 devices.
Your account now has 15 active devices.
Once you exceed 10 devices a warning is displayed in your console. It allows you to pay an extension for the remaining 10 months of your subscription.
You must pay for the extra 5 devices for 10 months or remove 5 devices from your account.
The total cost is calculated [extra devices] * [remainder of subscription]
i.e. 5 (devices) * 10 (months) = [total cost]
Customer support service by UserEcho