A closed mortgage is a restrictive type of mortgage that cannot be prepaid, renegotiated, or refinanced without paying breakage costs or a penalty to the lender.
With a closed mortgage, the interest rate is more attractive than an open mortgage because you are limited by how much extra you can pay towards your mortgage each year.
Whenever possible, be sure to select the “original mortgage balance pre-payment option” as this will enable you to pay off more in a year than the “current balance” alternative.