The solution method presented in this paper is of Trefftz type which uses exponential basis functions (EBFs) to solve composite plate problems. Following its success in the solution of plates using well-known theories (Composite Struct 2011;93:3112–9, 94:84–91 and 2012;94:2263–68), here we aim to apply the method to higher order shear deformation theories. In this paper we demonstrate the way that one can generally evaluate the EBFs for a laminated plate using a Zig–Zag theory. We present explicit relations for three-layer sandwich plates which have a wide range of applications in structural/mechanical engineering fields. The results of our numerical experiments on the bending analysis of composites with different boundary conditions and different configurations are provided and compared with those available in the literature. For further sudies we present some results for sandwich composite plates, including those with soft cores, as new benchmarks using the Zig–Zag theory.