The actual Illinois law covers real estate appraisal, not other kinds (ie, cars). However, it defines an appraisal as the act of forming an opinion about the va

The actual Illinois law covers real estate appraisal, not other kinds (ie, cars). However, it defines an appraisal as the act of forming an opinion about the value of a piece of real estate. It then forbids doing it without a license. Not doing it for money, not communicating your opinion, but forming it. There are explicit exceptions for realtors, banks involved in real estate lending, and for private use (ie, appaising your own house). So I would say Zestimates are clearly illegal according to the plain text of the law. However, I suspect this is one of those laws where a judge would find a convoluted reading to support his or her gut opinion that finding Zestimates illegal is ridiculous. I think you could also make a pretty reasonable claim that the freedom to form an opinion about the value of something is an unenumerated, but nonetheless inalienable right, and therefore the law is unconstitutional. Not a lawyer.