The K-Zone: estoppel

Under the traditional system of Equity, the word `estoppel' was used to describe a number of situations in which a person could be stopped (`estopped') from doing certain things. The term is not a precise one and, these days, is mostly used to describe what used to be called `estoppel by deed' (where `deed' has the sense of `action', not a legal undertaking).

In general, the law may act to estop actions of the following form:

one party, by word or action, gives another party to believe that a particular situation obtains, and
the other party acts on that understanding, and
that action leads to that party's detriment.

There are three main types of estoppel current in English law: PromissoryEstoppel, ProprietaryEstoppel, and EstoppelByRepresentation.

BasicPrinciples