Hi, my mortgage is an interest only one and the interest only period will expire about 5 years from now. I'm putting by a certain amount of money every month and plan to pay small amounts off from time to time. Can I pay those amounts off the full amount of the mortgage (ie the part I'm not paying off right now) without affecting the terms of my interest only loan, or do I have to pay it as more interest? Was hoping to pay these amounts off the full amount so I won't be overwhelmed by the full figure in five years time.