We solve the dual multijoint problem and prove the existence of so-called "factorisations" for arbitrary fields and multijoints of $k_j$-planes. More generally, we deduce a discrete analogue of a theorem due in essence to Bourgain and Guth. Our result is a universal statement which describes a property of the discrete wedge product without any explicit reference to multijoints and is stated as follows: Suppose that $k_1 + \ldots + k_d = n$. There is a constant $C=C(n)$ so that for any field $\mathbb{ F}$ and for any finitely supported function $S : \mathbb{ F}^n \rightarrow \mathbb{ R}_{ \geq 0}$, there are factorising functions $s_{ k_j} : \mathbb{ F}^n\times \mathrm{ Gr}(k_j, \mathbb{ F}^n)\rightarrow \mathbb{ R}_{ \geq 0}$ such that $$(V_1 \wedge\cdots\wedge V_d)S(p)^d \leq C\prod_{ j=1}^d s_{ k_j}(p, V_j),$$ for every $p\in \mathbb{ F}^n$ and every tuple of planes $V_j\in \mathrm{ Gr}(k_j, \mathbb{ F}^n)$, and $$\sum_{ p\in \pi_j} s(p, e(\pi_j)) =||S||_d$$ for every $k_j$-plane $\pi_j\subset \mathbb{ F}^n$, where $e(\pi_j)\in \mathrm{ Gr}(k_j,\mathbb{ F}^n)$ denotes the translate of $\pi_j$ that contains the origin and $\wedge$ denotes the discrete wedge product.
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