How is residency verified?

[Brian Barfoot]

This is purely theoretical but I want to know how banks check to see if someone is living in a property. I know that the down payment can be drastically lower and the rates are often better if you live in a property. Many banks won't even give loans for a non-occupied rental. What's to stop a person from going into a bank and claiming they intend to live in the property then once the financing is through, setting up tenants and moving on?