Second NIS Subscription

Hi

I bought a 5 device subscription to Internet Security a month ago but now find I need to cover more devices.

If I was near to the end of the 12 month subscription period I would just buy a new 10 device one and cut my losses on the unused period.

If I buy a second 5 device subscription now will I be able to add that to my account and have both 5 device subscriptions running at the same time? And then when the first subscription expires in 11 months time I can buy a 10 device subscription to cover everything and won't worry about the lost month on the second subscription.

Thank you