4-Fluorobenzyltriphenylphosphonium chloride (4-FBTC), a quaternary phosphonium salt, was synthesized, a single crystal was grown by slow evaporation method, and the structure was confirmed by single crystal XRD and spectral analyses. The single crystal XRD analysis showed the triclinic crystal structure with molecular formula, C50H48P2F2Cl2O3. Thermal studies were carried out at three different heating rates (5, 10 and 15 °C min−1) under N2 atmosphere, which shows the single-stage decomposition at all heating rates. The conventional, non-isothermal decomposition kinetic studies using model-free method were carried out to calculate the kinetic parameters like activation energy, pre-exponential factor, half-life and rate constant at various conversion percentages (1, 2.5, 5, 10 and 20%). Lifetime of 4-FBTC at room temperature for different conversion percentages was calculated to estimate the stability of the compound. Specific heat capacity and change in enthalpy were calculated using DSC analysis at 10 °C min−1 heating rate under N2 atmosphere.