what is estoppel 
the term estoppel refers to a legal principle that prevents someone from arguing something or asserting a right that contradicts what they previously said or agreed to by law put simply estoppel prevents one person from contradicting an action or statement from the past it is part of common law and is meant to prevent people from being unjustly wronged by the inconsistencies of another person s words or actions some of the most common forms of estoppel include collateral estoppel and promissory estoppel investopedia michela buttignol