The present invention relates to flame-retardant polycarbonate compositions and methods for increasing the flame-retardancy of polycarbonate compositions. An α,ω-alkoxy phenyl phenyloligosiloxane compound and an alkali metal sulfonate salt are added to the polycarbonate compositions. The addition of the α,ω-alkoxy phenyl phenyloligosiloxane compound and the alkali metal sulfonate salt produces a polycarbonate composition having a flame-retardance rating of UL 94V-0 at 2 mm thickness or less.