with a repayment mortgage you are paying for the interest as well at the capital from the outset - the endowment version means that you are paying for an insurance policy and interest, and hoping to repay the capital from the value of the policy when it matures. with a repayment, when you get the annual statement, you see the value of the loan going down each year. if yours doesn't then it sounds like an endowment, but you would have a life assurance endowment policy to go with it, you would have had a copy of that.