Do you have a "tax sell" property that was bought by your borrower and the original owner has one year to pay the taxes and redeem the property? I think I would want to know more about this property before lending money on it. If that's the case in one year you may not have a property securing your loan. Fortunately I have never had to deal with this so I'm in the dark of the legalities without doing some research.
Now with that said, I would consider this as part of the title insurance fee and exempt it based on that. Just my opinion.
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The opinions expressed are mine and they are not to be taken as legal advice.