  We revisit the impact of heavy neutrinos with masses in the MeV-GeV range on
neutrinoless double beta decay ($0\nu\beta\beta$) in view of updated results
for the lifetime of this process. Working in a minimal realistic extension of
the Standard Model by two right-handed neutrino flavours, we show that the
non-observation of $0\nu\beta\beta$ will impose strong bounds on the heavy
neutrino properties that are complementary to the limits obtained from Big Bang
Nucleosynthesis and collider searches. For an inverted mass hierarchy of the
light neutrinos we find that improved limits on $0\nu\beta\beta$ from
next-generation experiments will restrict the allowed parameter space for fixed
mass splitting to narrow bands in the mass-mixing plane. Further combining this
with the requirement to explain the baryon asymmetry of the universe via
leptogenesis reduces these bands to windows in parameter space that are
constrained in all directions and can be targeted by direct searches at
accelerators. For a normal mass hierarchy, only parts of the parameter space
can be probed by such experiments.
