Tree-seed algorithm (TSA) is a nature-inspired metaheuristic optimization algorithm. TSA is proposed for solving continuous optimization problems. In this work, TSA is modified with transfer functions for solving binary optimization problems. Continuous search space is mapped to binary search space with transfer functions. Four S-shaped and four V-shaped transfer functions are used for discretization. Uncapacitated facility location problem (UFLP) is a pure binary optimization problem. In order to measure the performance, 15 different sized (small, medium, large and extra-large) UFLPs are solved with eight different binary TSA in this work. Experimental results show that S-shaped transfer functions are better than V-shaped transfer functions on these problem sets.