The ATLAS and CMS experiments have an ambitious search program for charged Higgs bosons. The two main searches for $H^\pm$ at the LHC have traditionally been performed in the $\tau \nu$ and $t b$ decay channels, as they provide the opportunity to probe complementary regions of the Minimal SuperSymmetric Model (MSSM) parameter space. Charged Higgs bosons may decay also to light quarks, $H^\pm \to cs/cb$, which represent an additional probe for the mass range below $m_t$. In this work, we focus on $H^\pm \to \mu \nu$ as an alternative channel in the context of two Higgs doublet model type III. We explored the prospect of looking $pp\to tb H^\pm$, followed by $H^\pm\to\mu \nu$ signal at the LHC. Such a scenario appears in 2HDM type-III where couplings of the charged Higgs are enhanced to $\mu\nu$. Almost all the experimental searches rely on the production and decay of the charged Higgs are taken into account. We show that for a such scenario, the above signal is dominant for most of the parameter space, and $H^\pm\to \mu\nu$ can be an excellent complementary search.