Your new house has a pre-existing security system
Many times after you buy a new house, you’ll see that the previous owners didn’t take a home security system. All the components work, are hung in the best places, and are ready to go. In this instance, all you might have to do is to call and start a new monitoring contract. A Vivint installer will still show up to make sure there are no integration problems, and they might offer suggestions on an upgrade or two. It's a fast appointment, and you can get your alarm monitoring set up without having a bill for any new components -- unless you get some new devices.
The previous owners can transfer an existing Vivint contract to you for a one-time set-up fee to make the process simpler. If the outgoing residents are moving to a condo or retirement community, you keeping the home security service may be a part of the sale.
You are looking to move and take your existing components with you
You might need to bring your old home security components with you to your new house when you move. It should be fairly simple to transfer, as many components are portable. You can uninstall each device yourself or use a professional expert to come and dismantle the system. Then an expert will set up the same components -- and any new devices you want -- in your new home. The home security contract will keep the same.