Postal codes in Argentina

The Argentine postal code is a system that assigns at least one unique alphanumeric postal code to each municipality. Some larger cities have several codes starting at a base code, and the codes of all municipalities with a population over 500 additionally show the side of the block where the address is located.

Until 1998 Argentina employed a four-digit postal code for each municipality, with the first digit representing a region in the country, except in the case of the city of Buenos Aires (which had different postal codes starting in "1000" and with the other numbers varying according to the zone). The unique codes became the base for the newer system, officially called CPA ("Código Postal Argentino").

The CPA consists of three parts:
# A single letter that encodes the province (for example, "C" for Capital Federal, "Q" for Neuquén).
# Four digits (the old postal code or a variation of it on the last digits) showing the municipality.
# Three letters, identifying a side of the block where the address is located.

The CPA is not mandatory for private use, but companies that do mass mailings are benefited with discounts if they use the CPA. Despite this, the CPA is still not in wide use by private persons, and even government sources and private businesses often list the base code as in the old system. In order to ease the adoption of the new postal code, the former state mail company ("Correo Argentino") provides [http://www.correoargentino.com.ar/cpa/cons.htm a lookup facility in its website] . The CPA is intended to improve the quality and speed of mail delivery, but mail without a well-formed CPA will be delivered correctly as well.

This change can be compared with the ZIP+4 movement in the United States, in which the last four digits identify the block of the address.

The first letter in the CPA, which identifies the province, has its origins in the old Argentine license plates system, which gave each province a letter, usually its initial. Since several provinces share the same initial, a few odd assignments are found (such as "X" for Córdoba, "A" for Salta, and "N" for Misiones). See for a complete list.

ource

* [http://www.correoargentino.com.ar/consulta_cpa/cons_.php Código Postal Argentino] - Website of the "Correo Argentino" mail company, explaining the system (in Spanish).