  The current status of bound state quantum electrodynamics calculations of
transition energies for few-electron ions is reviewed. Evaluation of one and
two body QED correction is presented, as well as methods to evaluate many-body
effects that cannot beevaluated with present-day QED calculations. Experimental
methods, their evolution over time, as well as progress in accuracy are
presented. A detailed, quantitative, comparison between theory and experiment
is presented for transition energies in few-electron ions. In particular the
impact of the nuclear size correction on the quality of QED tests as a function
of the atomic number is discussed.The cases of hyperfine transition energies
and of bound-electron Land{\'e} $g$-factor are also considered.
