The steady‐state surface photovoltage technique was used to determine the optical absorption tail of InP:Mn, by extrapolation from the above‐band‐gap absorption spectrum. Reabsorbed recombination radiation is shown to have no effect on this procedure although it does raise the effective minority‐carrier diffusion length. The tail absorption coefficient of InP:Mn increases with hole density in the range of 4.1×1014cm to 5.3×1016cm−3. In the 1016cm−3range, the absorption coefficient appears to rise also with the density of dislocations.