the mortgage statements would need to at least detail the property address and have your name on them. I dont think it unrealistic to ask your mortgage provider for a letter stating that you are the owner of the house and what the current mortgage is. I am issued a letter every time the interest rate changes - but it has been constant over the last 18 months, so no letter issued. If you are going to put together all the paperwork associated with a Fiance visa, then would recommend you do this. good luck NS