Estoppel is a legal principle that prevents a person or entity from asserting a legal right or taking a legal position that contradicts or is inconsistent with its earlier position, behavior, or agreement. The person or entity is said to be “estopped” from changing its position, behavior, or agreement because another person or entity has relied on its earlier position, behavior, or agreement (detrimental reliance).
In Illinois, estoppel is a legal doctrine that can prevent an individual or entity from asserting a claim or a defense that is contrary to what they have previously stated or agreed to, especially when another party has relied on that earlier conduct to their detriment. This principle is designed to promote fairness and integrity in legal proceedings by holding parties accountable for their previous statements or actions. Estoppel can arise in various contexts, such as contract disputes, property rights, and employment relations. There are different types of estoppel, including promissory estoppel, equitable estoppel, and estoppel by deed, each with its own specific requirements and applications. Illinois courts will consider the specific facts of each case, including the representations made, the reliance by the other party, and the resulting detriment, to determine whether estoppel is appropriate.