Let \( G \) be a graph with vertex set \( V \) and no isolated vertices. A subset \( S \subseteq V \) is a semipaired dominating set of \( G \) if every vertex in \( V \setminus S \) is adjacent to a vertex in \( S \) and \( S \) can be partitioned into two-element subsets such that the vertices in each subset are at most distance two apart. We present a method of building trees having a unique minimum semipaired dominating set.