In this paper, we extend Landau's notion of `exchange relations' so as
to make sense for arbitrary planar algebras, which need not
necessarily be generated by its `$2$-boxes'. We show, as in Landau's
case, that these `higher exchange relation planar algebras' are
necessarily `finite dimensional', and that examples of such planar
algebras are given by all (even possibly reducible) depth two
subfactors, as well as planar algebras associated to subfactors with
principal graphs $E_6$ and $E_8$.