An overview is given of the use of multiplet approaches in X-ray absorption spectroscopy. Crystal field multiplet calculations are adequate for the 2p X-ray absorption spectra of 3d transition-metal ions, in contrast to the 2p X-ray photoemission spectra, which are dominated by charge-transfer effects due to core-hole screening. In the case of 1s X-ray absorption there are no multiplet effects and a single-particle density-functional theory or two-particle Bethe–Salpeter calculation is sufficient.