A mortgage life insurance policy is designed to pay off your mortgage when you die, so your loved ones can keep your home and won't be left with mortgage repayments they can't afford. It's usually available as a decreasing or level term policy.
With both decreasing and level term policies, a lump sum is paid if you die during the policy.
With level term policies, the same amount is paid out, no matter when you die. But with decreasing term policies, the payout amount decreases over time with the balance of your mortgage.
Decreasing term policies are usually cheaper, and suitable for repayment mortgages where the mortgage balance decreases over time. Level term life insurance may be better for you if you've got an interest-only mortgage with a fixed balance where repayments only cover the interest.