Only one person applying for the mortgage must live in the property to be considered a principal residence. To help you qualify for the home, you may add someone else to the mortgage application, but this co-borrower doesn’t need to live in your home for it to be considered your principal residence.
Think of it like this: In some cases—particularly with younger borrowers—you might be ready to buy your own home before you can fully qualify for the loan with your income. Adding other borrowers, like your parents, to your loan application can help you qualify for the mortgage you need. Their income combined with yours means that the three of you easily qualify for the loan. But that doesn’t mean your parents have to live with you for you to ultimately receive the mortgage.
For the lender’s purposes, your parents would be considered non-occupant co-borrowers. Their names and information are used to qualify you for the loan but not to determine your occupancy status. As long as you live in the home and call it your primary residence, you can take advantage of the low down-payment options, interest rates, and payments available for a principal residence.