With a repayment mortgage, each monthly payment pays off some of the capital (the loan itself) and some of the interest applied to the loan. This means that by the end of the mortgage term, you should have repaid the entire loan plus interest so will own the property outright. With an interest-only mortgage, you'll only repay the interest each month. The amount you borrowed won't be repaid until the end of the mortgage term. The vast majority of residential mortgages are on a repayment basis. This is because interest-only mortgages are much riskier. Buy-to-let mortgages are, however, often interest-only, so if you're purchasing a property to rent out, this may be a good option for you.