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
All-figure dialling exchange mnemonics that were possible under the existing system was being exhausted. The implementation of all-figure dialling and new local exchange codes in director areas allowed changes to be made to routing of calls into and out of these areas. The General Post Office issued subscriber trunk dialling (STD) codes for most areas during the late 1950s and early 1960s. The codes allowed subscribers to call other exchanges directly and without the assistance of an operator. To help the public remember the new codes they were represented by a recognisable combination of two letters and a number. The letters and