After you file

TT enters nothing.  haven't seen others reporting that TT double up on their mortgage interest deduction.  you can file a claim with TT, but honestly, it looks like it's your error. In addition, you should have review your return before filing. if you had you would have noticed the interest was doubled.  in any case, you will have to pay the taxes, TT will only pay the penalties and interest if the issue is caused by their calculation error. 

here's the link for information on filing a claim

https://ttlc.intuit.com/community/choosing-a-product/help/what-documents-do-i-need-to-submit-a-claim...