The Sources say that you may lie to
-save a life [Yoma 84b],
-keep the peace [Yevamot 65b; also Bava Metzia 87a],
-make people feel good [Ketubot 16b-17a],
-appear humble and modest [Bava Metzia 23b-24a], and
-protect yourself from loss or harm [Mishna Nedarim 27b-28a; Sotah 41b; Yevamot 65b and 63a; Sukkah 46b].
In all other situations, lying is ...