Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

Mortgage refinancing
If you selected a mortgage that allows additional payments to be credited against the principal rather than as early payment of normal installments, them yes, doing so will reduce the actual cost of the loan. You may have to explicitly instruct the bank to use the money this way each time, if prepay is their default assumption. Check with your lender, and/or read the terms of your mortgage, to find out if this is allowed and how to do it. If your mortgage doesn't allow additional payments against the principal, you may want to consider refinancing into a mortgage which does, or into a mortgage with shorter term and higher monthly payments, to obtain the same lower cost (modulo closing costs on the new mortgage; run the numbers.)