  We study the dominant signatures that arise in Higgs physics at colliders
when extending the Standard Model (SM) with a Yukawa interaction to heavy
neutral leptons (HNL), while suppressing their mixing to active neutrinos. We
focus on the production of HNLs from Higgs bosons that subsequently decay via
the Higgs to SM fermions to determine the experimental reach at the LHC
detectors and far detectors such as FASER and MATHUSLA. We also determine the
impact of precision Higgs constraints on beyond-SM parameters in this scenario.
