  We present a new method to compute higher-order corrections to physical
cross-sections, at Next-to-Leading Order and beyond. This method, based on the
Loop Tree Duality, leads to locally integrable expressions in four dimensions.
By introducing a physically motivated momentum mapping between the momenta
involved in the real and the virtual contributions, infrared singularities
naturally cancel at integrand level, without the need to introduce subtraction
counter-terms. Ultraviolet singularities are dealt with by using dual
representations of suitable counter-terms, with some subtleties regarding the
self-energy contributions. As an example, we apply this method to compute the
$1\to2$ decay rate in the context of a scalar toy model with massive particles.
