Your new place has a pre-existing security system
Many times after you purchase a house, you’ll find that the previous owners left a smart home system. All the devices function well, are placed in the correct places, and are ready to go. In this case, all you might have to do is to call and set up a new contract. A Vivint installer will still come to your home to make sure there are no integration problems, and they could offer suggestions on an upgrade or two. It's a quick trip, and you can have your monitoring set up without worrying about any new devices -- unless you add on.
The outgoing owners can move an existing Vivint contract to your family for a nominal transfer cost to make the process easier. If the previous owners downsize to a condo or smaller home, you keeping the Vivint service might be an addendum of the sale.
You want to move and take your old equipment with you
You may want to bring along your favorite smart devices with you to a new home when you move. Luckily, it's fairly simple to do, as many components are portable. You can remove each component by yourself or contact a professional expert to take down everything. Then an expert will hang the same components -- and any new devices you need -- in your new house. The home security contract will keep the same.