We present results for the inner-shell electron-impact excitation of Fe15+ using the intermediate-coupling frame transformation R-matrix approach in which Auger-plus-radiation damping has been included. The target and close-coupling expansions are both taken to be the 134 levels belonging to the configurations 2s22p63l, 2s22p53s3l, 2s22p53p2 and 2s22p53p3d. The comparison of Maxwell-averaged effective collision strengths with and without damping shows that the damping reduction is about 30 40% for many transitions at low temperatures, but up to 80% for a few transitions. As a consequence, the results of previous Dirac R-matrix calculations (Aggarwal and Keenan 2008 J. Phys. B: At. Mol. Opt. Phys. 41 015701) overestimate the effective collision strengths due to their omission of Auger-plus-radiation damping.