The vibrational modes of CO adsorbed on stoichiometric (1 1 1), (1 1 0) and (1 0 0) ceria surfaces have been determined from first principles density functional theory corrected for Coulomb correlations (DFT + U), which provides a consistent description of stoichiometric and reduced ceria. On adsorption on the (1 1 0) and (1 0 0) surfaces we observe a strong red shift of the CO stretching mode upon adsorption consistent with the formation of a carbonate species and in good agreement with experimental data.