Tubular profiles present geometric properties that enable a better structural behaviour in comparison with other cross‐sections when subjected to torsion. In regards to the joints between its elements, there are a few parameters that govern the design of the T‐joint resistance and change its failure mode. This paper presents a numerical investigation of square hollow sections (SHS) T‐joints with doubler plate reinforcement on the upper chord face under axial compression. The geometrical parameters are the slenderness chord, brace to chord width ratio, and reinforcement plate thickness combined with a certain level of axial compression on the chord. A numerical model has been developed compared with experimental tests. In addition, a parametric study was performed based in order to evaluate the parameters that influence the structural behaviour of reinforced T‐joint. Concerning outcomes, the increase of reinforcement plate thickness was responsible for the improvement of the joint capacity. In opposite to recommended by actual codes, the compression applied on the chord reduced the joint resistance mainly for those slender chord wall. Comparing with formulation from both code and other works, it was possible to conclude that there is an unsafe level from the actual codes.