Sold a property to a couple and did owner financing, and for whatever reason they didn’t provide their Social Security numbers on the Real Estate Tax Transfer form. Now tax time is here and my accountant is saying I need this info (or their tax ID number) to properly claim the mortgage interest, or I may face penalties. I reached out to the buyers, and they are refusing to provide this info (Althing they are certainly using my SSN to get their deduction). Are they or are they NOT required by law to provide this? What are my remedies if they won’t?
Please help.

I didn't find the right solution from the Internet.

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