Extensional faults in Southern Calabria (Italy) have been widely studied for their capability to generate high magnitude earthquakes (Mw 7-7.2). An example is the 1783 historical seismic sequence, which caused numerous fatalities near the villages located along the largest fault structures of this region, the Cittanova fault and the Serre fault. In this paper, we estimated the seismic potential of these two faults by a kinematic block modeling approach using GNSS data of both campaign points and permanent stations available within this area. Our results indicate that both faults are accommodating extensional velocity gradient (~ 1 mm/yr), with long-term slip rates (~ 2 mm/yr). A 3D mesh of triangular dislocation elements (TDEs) was used to estimate the spatial variability of the back-slip on fault planes, the corresponding interseismic coupling degree and the resolution capability related to the data spreading. This approach has allowed us to distinguish the fault areas where elastic seismic rupture is more likely to happen from those affected by aseismic creeping behaviour. Using our interseismic coupling results, we estimated a set of possible rupture scenarios in Southern Calabria, as well as calculated the corresponding interseismic moment accumulation rate, comparing it to the coseismic moment release rate achieved by previous studies. Thus, we achieved that, the Southern Calabria domain is accumulating an interseimic moment rate at most equal to 1.09 ×1015 Nm/yr, the equivalent of an earthquake of Mw 4 for each year.