Belle II has a broad $\tau$ physics program, in particular in searches for lepton flavour and lepton number violations. Belle~II profits from the relatively large $\tau$-pair production rate in the low background environment of $e^+e^-$ -collisions at 10.58~GeV.
Up to mid-2021 Belle~II collected a sample corresponding to $214~\text{fb}^{-1}$ of data.
We present a first measurement of the $\tau$ mass, the prospects for the $\tau$-lifetime measurement, and review the overall $\tau$ lepton physics program of Belle~II.