Camplus annual plan

If I subscribe to the 4-camera Cam Plus annual plan, will that process automatically give me a prorated refund of my 3 current individual annual Cam Plus subscriptions?

Perhaps, I need to cancel them myself before subscribing to the new plan?

I am only guessing it is safer to cancel individual plans before buying a different plan. When I once cancelled a cam plus subscription that had originally been charged an annual fee, I received almost instaneous email notification of the pro-rated refund.