Prepayments of mortgage usually just reduces the principle and do not apply to the interest. Ask the mortgage company if they will allow a payment of the interest and issue the 2017 1098 that includes any 2018 interest that was paid in 2017. If it is not on the 2017 1098 the IRS will not allow it.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
