We propose a computational scheme to solve the financial time-dependent 3D Heston–Hull–White PDE. In fact, a novel radial basis function (RBF) generated finite difference (FD) scheme associated with multiquadric RBF is introduced for solving this convection–diffusion–reaction equation. Non-uniform grids alongside the multiquadric RBF–FD technique are applied to obtain results of high accuracy in significant areas, at which the PDE problem is degenerate and discontinuous. The efficacy of the new scheme is shown through a series of numerical experiments.