Does the law of estoppel remedy reliance loss, or protect and grant expectations? In 1983 it was said that:‘This is a question that the courts must decide once and for all, and … they must not shirk from providing an answer by pretending that that answer will vary according to the facts of each particular case.’This article examines a view about this question which I shall call the ‘reliance loss theory’, which states that the normal response to a successful plea of estoppel is to compensate the claimant's reliance loss rather than to fulfil his expectations; in other words, that the court will, if possible, remedy the detriment he has already suffered in reliance upon what the other has said, without going to the lengths of obliging that other to abide by, or fulfil, what he has led the claimant to believe by his conduct or silence. The reliance loss theory has been presented as a description of what actually happens, but it also appears as an argument for what the law should be.