Our idealised morphodynamic numerical model simulates the temporal evolution of tidal sandbanks in sediment-scarce seas. The model solves the tide-topography interactions that drive sandbank evolution. The initial topography is a small sandbank in a shallow sea that is unaffected by coastal boundaries and where the sand supply is limited by the presence of a non-erodible layer. The growth and migration of this sandbank are simulated until a morphodynamic equilibrium is reached. The inputs are topographic, tidal, and numerical parameters, which are fully described in the README file. The outputs are the evolution of the bank topography over time and whether and equilibrium bank shape is reached. The topography of the last time step is the equilibrium profile (if one is reached). Importantly, our model is idealised, which means that it is meant to understand the dynamics of sandbank equilibria rather than predicting how a specific sandbank in a complex field setting