Liz Weston

Dear Liz: I want to save interest by making biweekly mortgage payments. My loan company said I couldn’t do that, but I wondered if there was a way by first paying the monthly mortgage and then making a half payment mid-month toward the next month’s due date, to get started. Then I’d make another half payment at the beginning of the following month. Ideally, this would all be arranged with autopay. I’m retired with a 4%, 30-year mortgage that has a $1,900 monthly payment and my retirement accounts are currently paying better returns.

Answer: You actually won’t save any interest until your mortgage is paid off, which could be 25 years from now if your mortgage is relatively recent. And getting a better return from your investments is a good reason not to accelerate your mortgage payments. You also shouldn’t prepay a mortgage if you have any other debt, lack a substantial emergency fund or are inadequately insured. (Those who are still working also should be maxing out their retirement contributions before making extra mortgage payments.)

With a biweekly payment plan, you’d pay half your monthly mortgage payment every two weeks. Instead of making 12 payments a year, you make the equivalent of 13 payments. Paying the extra amount helps you pay off the mortgage sooner. A bi-weekly payment plan would shave about four years off a $400,000 mortgage at 4%. The interest savings kick in once you’re mortgage-free. Then you’d save the $47,000 or so in interest you’d otherwise pay in the final years of the loan.

If you’re determined to do this, you should talk to your mortgage lender, because the arrangement you’re describing sounds a lot like the biweekly payments it won’t accept. You could hire a company that specializes in these arrangements, but the fees you pay for the service detract from your savings and aren’t really necessary. Instead, consider simply making an extra payment against the principal each month. Ask your lender how to set this up with autopay so that you’re actually paying principal. Otherwise, the extra amount might just be applied to the next month’s payment, defeating the purpose.