 Within Australia, the area code is only required to call from one area code to another.Australia is divided geographically into a small number of large area codes, some of which cover more than one state and territory.Prior to the introduction of eight-digit numbers in the early-to-mid-1990s, telephone numbers were seven digits in the major capital cities, with a double-digit area code, and six digits in other areas with a three-digit area code.