Trunk access code

A trunk prefix is a digit sequence to be dialed before a telephone number to initiate a telephone call for the purpose of selecting an appropriate telecommunications circuit by which the call is to be routed.

Making a domestic (national) telephone call usually requires the dialing of a single or two-digit national trunk prefix preceding any area codes and the destination subscriber number. In most countries, such as Australia, Germany, the Netherlands, Sweden, and the United Kingdom, the trunk prefix is 0. In the North American Numbering Plan (NANP) states, such as the U.S. and Canada, it is 1. For international telephone calls, the national trunk prefix is not dialed; instead, an international trunk prefix is typically required. Many countries use the sequence 00, but in the NANP it is 011.

Assume that a call is to be made to a customer in the Australian Area/State of Queensland with the local number of 3333 3333 and the area code 7.

A caller from outside Australia must dial the international call prefix of the originating country, plus the country calling code (61 in the case of Australia), plus the area code (7 in this case), and then the local subscriber number. Therefore a caller in the U.K. must dial 00 61 7 3333 3333, while a caller in the U.S.A. must dial 011 61 7 3333 3333.

Calling inter-area (within Australia) (e.g. from Western Australia—area code 8), a caller need not dial an international trunk prefix or a country code. However, the caller must at least dial the Australian trunk prefix (0) followed by the area code (7) and then the local subscriber number: 07 3333 3333. Calling from within the Queensland (7) area, a caller need only dial the telephone number: 3333 3333.

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