A mortgage is fixed on a specific property such as a house, and the lender can therefore force a sale of it, to recoup their money, if the payments are not kept up. That debt remains to be paid by the estate on death, so the executors or administrators must sell the property, keep up the payments from the monies left in the estate, or let the lender force a sale. It is treated as all other debts of the estate are, and, if the estate has not got sufficient funds left by the deceased to pay the debts , that's an end of the matter. As Peter says, even the Scots aren't that canny that the mortgage ceases to exist when the borrower dies !