CP violation in D decays is negligible in the standard model, and D decay asymmetries could be used in a charm-tau factory to look for or to constrain CP violation beyond the standard model. Asymmetries that depend on mixing are expected to be tiny because of the smallness of both mixing and CP violation. However, interference between standard-model CP-conserving amplitudes and beyond-the-standard-model CP-violating amplitudes relatively enhances CP asymmetries involving final state interaction phases. A charm-tau factory could be sensitive to a new physics scale Λ of O(1 TeV). As an example we consider the mode . This case is favorable because: (1) it involves a Cabibbo allowed mode, flavor specific, unsuppressed by color factors; (2) the FSI phase difference is known to be large; (3) CP violation coming from the standard model is negligible because penguin diagrams do not contribute (the “background” comes from interference through mixing and doubly Cabibbo suppressed decays). We consider lowest dimension operators contributing to that could come from: (i) chirality conserving interactions, or (ii) scalar boson couplings. As illustrative examples, we make explicit the left-right symmetric model with two generations, and charged Higgs boson exchange.