A: A joint owner of real estate can generally encumber the property, such as by mortgaging their interest, without permission of the other joint owner. If your brother falls behind on payments, the lender could foreclose on his interest in the property. They could then probably force a sale of the property in an action for partition. To prevent this, one option would be to pay off or assume the loan and buy out your brother's interest in the real estate. Since he is behind on his loan, you could probably drive a pretty hard bargain. If you do nothing, the lender could eventually take your brother's interest in the property and force a sale.