You’re moving into a place with home security components
A new house may come with an installed security system. All the components work, are placed in the best places, and are ready to go. In this case, just get the phone to call and establish a new monitoring contract. A Vivint expert will still come to your home to make sure there are no compatibility problems, and they may offer options on upgrades. It's a preliminary visit, and you can have your alarm monitoring set up without having a bill for any new components -- unless you get some new devices.
The outgoing homeowners can transfer an existing Vivint contract to your family for a one-time set-up cost to make the transfer easier. If the outgoing residents downsize to a condo or retirement community, you keeping the Vivint service may be a part of the sale.
You want to move and take your existing devices with you
You might need to take your existing Vivint system with you to your new place when you move. That’s pretty easy to transfer, as modern components are portable. You can take down each device yourself or call a Vivint installer to come and take care of everything. Then an expert will set up the same devices -- and any smart items you want to add -- in your new house. The home security contract will remain the same.