Here's how to enter a mortgage interest on a seller-financed loan in TurboTax. You will need the name, address, and Social Security number of the person you made the mortgage payments to.

• Click the Federal Taxes tab.
• Click Deductions & Credits.
• Click "I'll choose what I work on" or "Jump to a full list."
• On the screen "Your 2016 Deductions & Credits," under "Your Home" click the Start button for "Mortgage Interest, Refinancing, and Insurance."
  
• The first screen asks for the lender's name. Enter the name of the person you made the mortgage payments to.
• The next screen says "Tell Us More About Your Loan" and has several checkboxes. Check the box that says "I did not receive a 1098."
• On the next screen, enter the amount of interest that you paid. Enter only the interest portion of your payments, not the full amount that you paid.
• The next screen asks for some additional information about your mortgage. Enter the requested information.
• The next screen asks if it's a seller-financed loan. Click Yes.
• On the next screen enter the seller's address and Social Security number.