You moved into a home with an existing security system
Sometimes when people close on a home, a home security system is already in use. All the components work, are placed in the correct areas, and are ready to go. In this instance, you might find that you have to call and establish a new service contract. A Vivint installer will still come out to ensure there are no usability problems, and they might offer options on where you should replace bad outdated components. It's a quick visit, and you can have your 24/7 monitoring set up without worrying about any new components -- unless you make additions.
The previous owners can move an existing Vivint contract to your family for a nominal transfer fee to make your life a snap. If the outgoing residents are moving to an apartment complex or smaller home, you keeping the security service may be a part of the sale.
You need to move and take your home security components with you
You may want to bring along your existing home security components with you to your new home when you move. Luckily, it's pretty easy to transfer, as modern smart devices are portable. You can remove each device yourself or call a professional expert to come and dismantle everything. Then an expert will put in the same components -- and any additions you need to have -- in the new place. And your home security contract will stay the same.