Before paying off your mortgage loan make sure you obtain the payoff statement.  The lender can provide a payoff statement and the final amount to be paid to release their lien. Then you can know the principal balance, interest up to the date of closing, penalties (if any), and other charges the lender may charge to obtain the payoff, such as a processing fee; if there is a pre-payment penalty on the loan, it would show up here.

The payoff is usually obtained by the title company. If the transaction is a sale, the payoff will be subtracted from the proceeds the seller receives. If the transaction is a refinance, the payoff will be subtracted from the loan proceeds provided by the new lender. Relying on the remaining principal balance alone will not be sufficient to pay off the loan.

Remember to obtain a payoff statement so you will know the final amount due to the lender.