The objective of this work is to numerically validate a previously formulated detailed chemical kinetics mechanism for the liquid phase decomposition of guanidinium azotetrazolate (GzT). GzT is of keen interest to researchers because of its energetic properties therefore it is critical to thoroughly understand the chemistry involved in its decomposition. The present work is a step in this direction. The reaction mechanism used in the present model, which consists of 76 species and 107 elementary reactions along with their kinetic parameters, was compiled from two previously published works. Simulations of the mass loss in thermogravimetric analysis and heat flow in differential scanning calorimetry were carried out using a numerical model. Results of the simulations were found to match satisfactorily with those from the experiments. Critical pathways in the GzT reaction mechanism were also identified by carrying out a sensitivity analysis.