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The transition metal dichalcogenide 1T-TaS2 is a layered compound that exhibits a series of increasingly commensurate charge density wave phases with decreasing temperature, including a low-temperature insulating phase. For a single 1T-TaS2 layer, with an odd number of electrons per Star-of-David cluster, the insulating behaviour may be attributed to Mott localisation. However, the stacking arrangement of multiple layers can lead to doubling of the unit cell, where the nature of the insulating state is ambiguous. Furthermore, the various possible stacking terminations lead to surface states with non-trivial interplay between band-insulating and Mott-insulating behaviour.