I am taking out a mortgage on a property and my partner (not on mortgage as didn't have enough permanent work years) is going to be paying towards the mortgage each month, and paying a lump sum (approx 13k) to me for the house to reduce amount of mortgage needed. Questions are: The bank will want to know where the extra funds are coming from so it will either be a gift from my partner as it's under the 19k, or could it be treated as a loan with 0% interest? Also, will my partners payments towards the mortgage be taxed or what is the best way to deal with this. We are young first time buyers and trying to get the lowest interest possible on mortgage, but yet don't want to find we owe tax instead. sorry not worded too well.