The polar-to-nonpolar interface of DyScO3 and SrTiO3 was studied using density functional theory. Due to the polar discontinuity arising from nominally charged DyO or ScO2 layers, sharp interfaces induce a strong ferroelectriclike polarization in the SrTiO3, while in chemically mixed interfaces this discontinuity is avoided and no such polarization can be found. In both scenarios the interface remains insulating with only a small reduction of the band gap. Our calculations show that mixed interfaces are energetically more favorable than sharp ones, in agreement with recent experimental results that confirmed intermixing at these interfaces.