We discuss the effects of lepton-number-violating (LNV) interactions in neutrinoless double beta decay ($0\nu\beta\beta$), assuming that LNV arises either from light sterile neutrinos or from energy scales well above the electroweak scale. In this scenario, LNV can be described by an effective field theory (EFT), consisting of the standard model (SM), supplemented by higher-dimensional operators made up from SM fields and the sterile neutrino. We summarize the steps needed to obtain expressions for the $0\nu\beta\beta$ half-lives in terms of the LNV operators. We pay particular attention to the matching of the quark-level interactions onto chiral EFT, which involves nucleons and pions as the degrees of freedom. This theory allows one to derive LNV potentials between nucleons, which, together with many-body calculations, determine the decay rates of nuclei that are used in experiments. We will show that the matching onto chiral EFT requires the inclusion of a contact interaction at leading order and discuss a model estimate of the associated hadronic matrix element. We conclude by illustrating the constraints on the higher dimensional operators.