[2024] UKUT 81 (LC)

As we can see from the summary of the principles seen in Tinkler, estoppel by convention is a technical doctrine. It is useful in the contexts in which it was developed, namely commercial disputes where parties have adopted a conventional reading of, for example, a lease or a contract. Its requirements are demanding; the mere sharing of a common assumption is not enough, there has to be communication and there has to be an intention that the person alleging the estoppel was to rely upon the communicated assumption.

As we shall see in the present case, those requirements are going to be difficult to satisfy in a service charge dispute where arrangements can drift on for years without there being any communication about them. The Landlord and Tenant Act 1985 is intended to provide a workable code for landlords and tenants in the resolution of disputes about service charges. In a service charge case where the leaseholder has behaved in such a way that it is unfair to allow them to change tune now, it is tempting to explore estoppel because the situation, put like that, feels estoppel-ish. But there is no need to give in to that temptation; section 27A(4)(a) should be used instead. Its effect is that for the leaseholder to be prevented from changing its position and challenging something that it had previously gone along with, all that is needed is admission or agreement; there is no need to prove estoppel.