The influence of the pH and Cu(II) concentration on copper electrodeposition in 1 M NH4Cl was studied. Triangular potential scan voltammetry and chronoamperometry techniques were used to understand the nature and stability of the copper species present at the interface. A relationship was found between the species present in solution and those observed at the interface when the pH and Cu(II) concentration were varied during Cu(II) deposition in the presence of NH4Cl. A clearer understanding of the current-voltage curves, the kinetics of the copper deposition process and the reversible potentials of various copper complex redox couples was obtained.