“Post code” redirects here. For computer POST codes, see Power-on self-test.
Postcodes are generally clearly visible outside Australia Post offices.
A postal code (known in various countries as a post code, postcode, or ZIP code) is a series of letters and/or digits appended to a postal address for the purpose of sorting mail. Once postal codes were introduced, other applications became possible.
In February 2005, 117 of the 190 member countries of the Universal Postal Union had postal code systems. Countries that do not have national systems include Ireland and Panama.
Although postal codes are usually assigned to geographical areas, special codes are sometimes assigned to individual addresses or to institutions that receive large volumes of mail, such as government agencies and large commercial companies. One example is the French CEDEX system.