Events containing high-$P_T$ multi-leptons were sought
at HERA by the H1 and ZEUS collaborations.
Experimental data were compared to simulations of
$\gamma \gamma \rightarrow l^+ l^-$ processes,
and H1 extracted the total and differential cross sections
of the processes.

The doubly-charged Higgs, which decays into lepton pairs,
was analysed by H1 as a possible source of the multi-electron
events, which have been observed at high invariant masses.