This paper introduces a modified fundamental solution for bending analysis of thin and thick plates with arbitrary shapes. Kernel function terms representing the effect of transverse stresses have been separated, thus allowing efficient computation, within which such terms can be cancelled for thin plates. Boundary analysis of the domain loading terms for cases with uniform or linearly-distributed loading, and concentrated shear forces and bending moments are presented. A treatment of corner and singularity problems is also provided. Case studies with different shapes and boundary conditions, including a very thin example, have been analysed and the boundary element results were compared with corresponding analytical solutions. It is clear that the introduced derivations perform very well with a wide range of plate thickness.