One problem with bras is the assumptions bra producers make about the relationship between rib cage and breast/cup size. Would not be such an issue if the width of the band were uniform, but they are not. Good luck with finding extenders that match the width of the band at the same shop one finds a bra that otherwise fits. At least in the USA. Don't know if women across the pond experience the same frustration. Know from my sis and other friends that this is a common problem on this side of the pond.