I am buying my first house costing $500,000. I am getting the FHOG and will be residing at the residence for 6 months following settlement. I will then turn it into a IP and move back in with the folks. I will have a offset account (leaving another 100k in there) and will be paying interest only for the initial 6 months. Am i right in thinking that once i turn it into a IP the interest becomes tax deductible but while its my main residence i cant right?