I have three Pro 3 cameras with a 3-month subscription plan and a Video Doorbell with a separate 3-month plan that I bought at about the same time. When the subscription ends, can I combine all 4 cameras on one plan and if so, how do I do that?
If you purchase a 5 camera bundle subscription plan, you will be able to move the cameras into that plan once the trials expire. For more information on subscription plans, take a look here: What are the available Arlo subscription plans and how much cloud recording is available?
Make sure to wait until the 1st free trial is almost up, if not you will be charged thus rendering the 1st free trial basically useless. Move the other camera or doorbell onto the new subscription a day before it expires. That way you'll get to use most of the free subscriptions before paying anything.