Abstract The 63Cu and 17O NMR were measured in oriented ceramic samples of Tl 2Ba 2Ca 2Cu 3O 10−δ with various Tc values in the normal and superconducting states. The quadrupole coupling constants for copper and oxygen from different CuO 2 layers were obtained. The doping variation of the valence contribution to the electric field gradient at the Cu site was used for estimation of the hole concentration. In the overdoped Tl2223 sample with T c( δ 1) < T c opt( δ opt> δ 1) the charge density in the inner layer (with four-fold oxygen coordination for Cu) differs from one in the outer plane (with five-fold oxygen coordination for Cu). Our results have shown that the inhomogeneity of the charge distribution disappears in the underdoping regime.