answer:The contract should state whether you can pay extra payments toward principal or not, or if a pre-payment penalty will be incurred. Most reputable companies will let you pay toward the principal, thus, reducing your overall interest due. However, your question seems to ask whether you can have all of your payment go to principal and none go to interest. The answer to this is usually no, you need to pay the interest that has accrued to the point of your payment before money can be applied toward principal. I have never heard of being able to only pay principal with no interest whatsoever; they did have interest only mortgages as a big thing before the bubble burst. I do not know the legalities of the request. Most creditors want to make sure you pay the interest because that is where they make their money. The principal is what they risked, not what they gain.