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
Area code 000 because there is no requirement that caller id data represent a valid telephone number. Area code 000 Area code 000 is not a valid number in any country where dialling '0' reaches an operator. Area code 000 is not a valid North American Numbering Plan exchange or area code. It is invalid in the European Union and many other nations where '0' is reserved as a trunk prefix and '00' as an international call prefix. In Australia, 000 is reserved as an emergency telephone number. This code may show up as part of a number on a caller id system