Correo Argentino, Argentina's mail service, has an office in most neighborhoods; some locutorios (phone centers) serve as collection points and sell stamps. Postboxes are dark blue and yellow, but there are very few that are not directly outside—or even inside—post offices.
Mail delivery is far from dependable: it can take 6–21 days for standard letters and postcards to get to the United States. Regular airmail letters cost 4.50 pesos for up to 20 grams. If you want to be sure something will arrive, sent it by correo certificado (registered mail), which costs 11.50 pesos for international letters up to 20 grams. Valuable items are best sent with private express services such as DHL, UPS, or FedEx—delivery within one to two days for a 5 kilogram package starts at 500 pesos.
Argentina's post-code system is based on a four-digit code. In 1998 each province was assigned a letter (the city of Buenos Aires is "C," for instance), which goes before the number code, and each city block is identified by three letters afterward (such as ABD). In practice, however, only very big cities use these complete postal codes (which look like C1234ABC), whereas the rest of Argentina uses the basic number code (1234, for example).
Correo Argentino (Av. Córdoba 663, Microcentro, Buenos Aires, Buenos Aires, C1054ZAB. 11/4891–9191. www.correoargentino.com.ar.)
DHL (Av. Córdoba 783, Microcentro, Buenos Aires, Buenos Aires, C1054AAG. 810/1223–345. www.dhl.com.ar. C to Lavalle or San Martín.)
Federal Express (25 de Mayo 386, Microcentro, Buenos Aires, Buenos Aires, C1002ABH. 810/333–3339. www.fedex.com. B to L. N. Alem.)
UPS (Pte. Luis Saenz Peña 1351, Constitución, Buenos Aires, Buenos Aires, C1135ABC. 800/2222-2877. www.ups.com. E to San José.)