Telephone numbers in Australia plan (including the "Trunk Access Code"), presented in domestic format. (Geographical region boundaries do not exactly follow State borders.) The current numbering plan would appear to be sufficient to cope with potential increase in demand for services for quite some time to come. The 06 and 09 area codes are completely unused. In addition, each current area code has large number "ranges" unallocated. When dialling from outside Australia, after dialling the appropriate International Access Code it is necessary to dial the Country Code for Australia (61) followed by the nine digit "National 'Significant' Number". (The + symbol is used to
Former Australian dialling codes Former Australian dialling codes The format of telephone numbers in Australia has changed over time to allow for the expansion of the subscriber base as technology has improved. The introduction of subscriber trunk dialling was slow, partly because of the distances of exchanges in some areas and partly due to the use of manual exchanges well into the 1980s. Initially, dialing codes covered a very small area, sometimes only one exchange, but gradually exchanges conglomerated to become large area codes. The length of codes varied; as early as 1971, some localities had area codes as long as seven digits, while