I had seller financing on my home in 2018 but do not have the seller's Social Security number. How can I file using TurboTax? Can I file on-line?

[KrisD]

No, if you are paying interest to an individual, you need their Social Security number or EIN. 

If they don't want to give you their social security number, have them get a EIN. 

Home mortgage interest is only deductible if you Itemize deductions. It the Standard deduction is more, the interest won't matter on the Federal return. 

https://www.irs.gov/businesses/small-businesses-self-employed/apply-for-an-employer-identification-n...