Tauonic $B$ decays and Higgs mediated flavour violation

In these proceedings we review the impact of the tauonic $B$ decays $B\to \tau \nu$, $B\to D\tau \nu$ and $B\to D^{\ast }\tau \nu$ on Higgs mediated flavour violation. For this purpose we study a 2HDM with generic flavour structure (of type III). We find that despite the stringent constraints from FCNC processes sizable effects in tauonic $B$ decays are possible if top-related flavour violation is large and that the tensions with the SM predictions can be resolved even when taking into account the recent CMS bounds on $A^0\to {\tau }^{+}{\tau }^{-}$.