Even though the standard model (SM) of particle physics aligns with many experimental results, the need to expand the SM arises to address important open questions. The most suitable and minimal extension of the SM is the local gauge group , which is known as the ‘3-3-1 model’ in the literature. In this paper, a democratic mass matrix (DMM) approach is applied to the lepton sector of one of the anomaly free 3-3-1 model. It is demonstrated that the DMM parametrization can fit with experimental mass and Pontecorvo–Maki–Nakagawa–Sakata matrix (PMNS) data. Also we have presented an extended PMNS matrix elements for the gauge bosons of (and K 0, ) which mediate between new heavy neutrinos and leptons (known neutrinos).