Relative 1σ uncertainty of the number of AGN detectable in at least one Euclid band (N_AGN) for each of the quantified sources of uncertainty introduced in this work. Displayed in this plot are uncertainties introduced by the X-ray luminosity function (XLF), infrared bolometric correction dispersion (IRBC), X-ray bolometric correction dispersion (XBC) and unobscured AGN emission lines (EL) for which a lower limit was quantified using the Lyα emission line and Hα+[N II] complex. The expected relative Poisson noise for the EDS, calculated as $\sigma =\sqrt{N_{\mathrm{AGN}}}$, is indicated by the shaded blue region.