Error on the mean redshift determination ⟨z⟩−⟨z⟩_truth for ten Euclid Flagship tomographic bins, for each of our four photometric redshift catalogues (‘mean Rubin’ in dark purple, ‘mc Rubin’ in purple, ‘mean’ in dark green, and ‘mc’ in light green, with dark and light shades indicating 68.3% and 95.5% uncertainties). The grey bands show the target uncertainties for Euclid. Two n(z) fitting methods are shown: the shifted-true model (left, Sect. 3.3.1) and the suppressed-GP model (right, Sect. 3.3.2), each fit to clustering redshift measurements made with spectroscopic sample bias corrections (i.e. method 2, Sect. 3.1).