Stacking yearly subscription

Hi, new to ring products so unsure if this has been answered but cannot find any information to answer my question. With ring protect plus are you able to ‘stack’ the yearly subscription. For example with other online subscription models you can pay the year fee and stack for multiple years to run back to back. My intention is to pay £400 for 5 years of subscription so I dot have to be worried about price increases during this time before investing into the ring ecosystem