Let G be a finite group, let
${\text{Irr}}(G)$
be the set of all irreducible complex characters of G and let
$\chi \in {\text{Irr}}(G)$
. Define the codegrees,
${\text{cod}}(\chi ) = |G: {\text{ker}}\chi |/\chi (1)$
and
${\text{cod}}(G) = \{{\text{cod}}(\chi ) \mid \chi \in {\text{Irr}}(G)\} $
. We show that the simple group
${\text{PSL}}(2,q)$
, for a prime power
$q>3$
, is uniquely determined by the set of its codegrees.