<prompt> Human: This seems like a question that would come up a lot its a spin on what do I do with x, but Ive searched through the FAQ, other subreddits, google, etc., and I cant find advice thats quite right for this situation.I am buying and selling a home. While my current home was still for sale, I put a low offer in on a new house, and it was accepted. I have enough money to make a reasonable down payment on the new house without selling my old one. However, the mortgage will be larger in this scenario than it would be if I had done things in the right order. When my old home sells, I expect to clear about 80k after agent fees, paying off the old mortgage, etc.. Im struggling with what to do with that money, which will most likely be available 1-2 months after I close on my new house. Should I refinance quickly to a new 30 year mortgage lower my principal, or should I put the 80k back into the existing mortgage without refinancing thus not having to pay closing costs twice, but keeping a much higher monthly payment? Or is there a better way?New house cost: 170kNew mortgage principal: 153kNew mortgage payment without refi, 30 y fixed: 709Amount cleared from old mortgage: 80kNew mortgage payment with refi, 30 y fixed: 338  <response>: I dont have advice on applying the to your mortgage or investing it elsewhere, however I know a few lenders that will reamoratize the loan with a large principle payment for an administrative fee, rather than a full set of closing costs. If you do decide to apply the to principle, you should see if that is an option rather than a full on refinance. There are also a lot of very low cost refinance options that may make just as much sense. 