@Opus 17 there has been discussion that Turbo Tax has some challenges with multiple 1098s. I have multiple refinances on the same loan for the same property. Principal has decreased over time and no additional loans were taken out. The advice is to add up all the mortgage interest in box 1 across all the 1098s and put it as one number. For box 2, I’m not sure how to address it. For box 3, the advice was to put the original mortgage origination date back in 2014, not the new dates that the refinance happened.
