For any indoor antenna test range (planar/cylindrical/spherical/compact), room scattering is one of the most significant terms within the overall uncertainty budget, especially when the range is pushed to operate outside its optimal working frequency range, either lower or higher than its designed frequency range. A frequency domain mode filtering based measurement technique has been used to reduce the range scattering in the past decade. Although this technique has been extensively examined and validated through measurements, comparatively little validation has been reported using full-wave three-dimensional computational electromagnetic (EM) simulation because of the huge computational effort required. Built upon the successful, recent, development of an EM model for cylindrical mode based far-field antenna scattering suppression, that study is extended to consider the more complicated case of the spherical far-field range. For the first time, an EM model of the spherical far-field measurement was constructed and used to verify this measurement and post-processing technique. The EM modelling technique is detailed, and initial results are presented which show good agreement between the “true” far-field and the perturbed far-field with scattering suppression processing having been applied. The criterion of how to select the transformation centre point for optimal scattering suppression is examined and best practice proposed.