Several severely damaged or collapsed Geosynthetic reinforced soil (GRS) walls have been reported during various earthquakes in the past. This emphasizes the further investigation into the vulnerability of the GRS wall under dynamic conditions. The external and internal stability ensures the safety of the GRS wall. The internal stability involves the consideration of potential failure plane for reinforcement design. Several geometric considerations of potential failure plane have been found in the literature, i.e., linear, multilinear, log-spiral. The paper presents a pseudo-static limit equilibrium method for internal stability analysis for design of reinforcement for a vertical GRS wall with a uniform surcharge load on the horizontal top. The study involves the consideration of n-degree polynomial potential failure plane for internal stability, and the geometry of the failure plane considered in the present study has been compared with the finite element analysis and Federal Highway Authority (FHWA) recommendations. The variation of seismic acceleration coefficients on the strength and length has also been investigated. It has also been found that the critical failure plane is highly influenced by the acceleration coefficients as an increase in horizontal acceleration coefficients increases the area of the active zone.