Most British mortgage holders live with uncertainty. They always face the risk of higher repayment costs through no fault of their own. A change in interest rates, a financial crisis, a war started by Donald Trump, or turmoil in global markets can suddenly increase the cost of keeping a roof over their heads. But it does not have to be this way. In the United States, millions of homeowners have fixed-rate mortgages that last for the entire life of their loan.