You’re buying a house with home security devices
A new home may come with an installed security system. All the devices work, are placed in the correct places, and are ready to go. In this example, just turn on the phone to call and establish a new monitoring contract. A Vivint expert will still show up to make sure there are no compatibility issues, and they may offer suggestions on an upgrade or two. It's a preliminary trip, and you can get your 24/7 monitoring set up without having a bill for any new components -- unless you get some new devices.
The previous owners can move an existing Vivint contract to you for a one-time set-up fee to make the transfer easier. If the owners downsize to an apartment or retirement community, turning over the home security service may be a part of the sale.
You are looking to move and take your home security components with you
You might need to bring your old home security components with you to your new home when you move. It should be pretty simple to transfer, as many alarms and smart devices are wireless. You can take down each alarm or camera yourself or contact a Vivint expert to take down everything. Then an expert will put in the same components -- and any smart items you want to add -- in the new place. And your home security contract will remain the same.