EFX may refer to: EFX (show), a Las Vegas show EFX (album), an album of the show Enerflex Systems, a Canadian company listed as EFX on the Toronto Stock Exchange Equifax, a U.S. consumer credit reporting agency listed as EFX on the New York Stock Exchange Effects Extension (EFX), a set of digital signal processing extensions for the OpenAL audio API .efx, the Everett Efax file format, see List of file formats EFX item allocation - a rule for fair allocation of indivisible objects among people with different preferences.
See also FX (disambiguation) Das EFX, an American hip-hop group