  The long distance correction to the total decay width of the $\tau^{\pm}\to
K^{0}\pi^{\pm}\nu$ decay is calculated in a model independent approach where a
discrimination of photons in the Bremmstrahlung process is assumed. This
correction is completely free of UV and IR singularities and moreover, it
satisfies electromagnetic gauge invariance. The result of this work can be
applied on the tau decays: $\tau^{\pm}\to \pi^{\pm}\pi^{0}\nu,
K^{\pm}\pi^{0}\nu$.
