Equitable estoppel is an American counterpart to the English concept of estoppel by representation of fact. The representation that invokes equitable estoppel applies to representations made by both words and/ or conduct. Although the representation must be clear and unambiguous, a representation under equitable estoppel can also be inferred from silence when there is a duty to speak or when negligence has arisen from a duty of care.
The English counterpart, Estoppel by Representation of Fact, is usually implemented as a defense, although in certain cases it can be a support in a cause of action or a counterclaim.
American equitable estoppel is commonly summarized as:
Facts that are concealed,
Hiding knowledge of true facts,
Acting with fraudulent intent,
Acting from unjust inducement,
Benefiting from detrimental reliance,
Injury to the complainant, and
A clear, concise, unequivocal proof of act, which in no way involves implication.
Equitable estoppel is alternatively known as estoppel in pais and is meant to protect a party to a contract from being harmed by the voluntary conduct of another party. It is immaterial to a finding of equitable estoppel whether the voluntary conduct is action, silence, acquiescence, or the concealment of material facts.
When equitable estoppel is considered estoppel by laches, it is a form of estoppel that precludes a party from being allowed to bring an action because the party knowingly failed to claim or enforce one of their legal rights in a proper period of time.