Boyfriend buying into property

[Account Closed]

My boyfriend and I moved in together in October in NH. I purchased the home with my credit, under my name, with my own downpayment and created a written agreement that he would pay half the mortgage and household expenses when he moved in and also gave him an option to buy into the house when he was able by giving my half the downpayment. He would now like to buy into the house and pay half of the downpayment. My understanding is that we would have to sign a quitclaim deed (???) to add him to the deed (at this time, the rates are higher on the mortgage so I don't want to refinance to both our names at a higher rate). Are we facing having to pay additional taxes for this transaction?