Postal codes in Argentina

Postal codes in Argentina are called códigos postales. 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, Argentine Postal Code).

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 a look-up feature on 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.

The CPA consists of three parts:

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 ISO 3166-2:AR for a complete list.

The four digits could be grouped as the following:

A combination of three letters that identifies a side of a city block.

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