  The only possible doubly-charged scalar decays into two Standard Model
particles are into pairs of same-sign charged leptons, H$^{\pm\pm}\rightarrow
{l}^\pm {l}^\pm, {l} = e, \mu, \tau$, or gauge bosons, H$^{\pm\pm}\rightarrow
W^\pm W^\pm$; being necessary the observation of both to assert the violation
of lepton number. However, present ATLAS and CMS limits on doubly-charged
scalar production are obtained under specific assumptions on its branching
fractions into dileptons only. Although they can be extended to include decays
into dibosons and lepton number violating processes. Moreover, the production
rates also depend on the type of electroweak multiplet H$^{\pm\pm}$ belongs to.
We classify the possible alternatives and provide the Feynman rules and codes
for generating the corresponding signals for pair and associated doubly-charged
scalar production, including the leading contribution from the $s$-channel
exchange of electroweak gauge bosons as well as the vector-boson fusion
corrections. Then, using the same analysis criteria as the LHC collaborations
we estimate the limits on the H$^{\pm\pm}$ mass as a function of the
electroweak multiplet it belongs to, and obtain the bounds on the lepton number
violating processes $pp\rightarrow {\rm H}^{\pm\pm}{\rm H}^{\mp\mp} \rightarrow
{\ell}^\pm {\ell}^\pm W^\mp W^\mp$ and $pp\rightarrow {\rm H}^{\pm\pm}{\rm
H}^{\mp} \rightarrow {\ell}^\pm {\ell}^\pm W^\mp Z$, $\ell = e, \mu$, implied
by the ATLAS and CMS doubly-charged scalar searches.
