Abstract The effect of AC-induced interference on the localised corrosion resistance of passive metals is analysed and discussed on the basis of laboratory test results. Two conditions were considered: 1. AC interference on stainless steel specimens in neutral solution varying chlorides concentration; 2. AC interference on carbon steel rebar in chloride containing concrete. Applied AC was in the range of 10 A/m2 to 500 A/m2. Results allow evaluating the effect of AC on: time-to-corrosion, critical chloride threshold, AC critical current density and corrosion morphology.