http://www.migraciones.gov.ar/accesibleingles/?noticia=1632 (so far, in Spanish only)

AS OF JANUARY 7, 2013 pre-paid on-line reciprocity fees before departure and arrival will be payable for all entries into Argentina for Americans, Australian or Canadians, whether by land , sea, or flight. :(

Pre-payment has already started, no problems reported so far, it just does not become obligatory until 28 DECEMEBER 2012 for flights to Aeroparque or for Ezeiza International Airport, BA. As of Right now , it is still an option to paying on arrival. As of January 7, 2013, it is scheduled to apply for all entry points, everyhwehere, by land sea or flight.

You register for the pre-payment site and pay here:

https://virtual.provincianet.com.ar/ArgentineTaxes/

(above link updated June 18, 2014)

Also, an explanation of the procedure is set out there as well.

The National Immigration Agency has changed the method by which tourists and business visitors from the US, Canada, and Australia will be required to pay in order to gain visa entry to Argentina. The reciprocity fee will shortly no longer be payable at the airport upon arrival. Instead the payment must be carried out online, prior to arrival, using the credit card based Provincia Payment System.

ON 28th December 2012 for Ezeiza International Airport AND AEP in BA, it becomes a requirement to pre-pay. A press release clearly states that “after these dates cash payments will not be accepted at the airport”.

The change in payment method follows a decision to increase the fee for US citizens from US$140 to US$160, which came into effect in April of this year.

A press release from the US state department offers these instructions for how to pay the reciprocity fee online:

1) Enter the web site www.migraciones.gov.ar or www.provinciapagos.com.ar of Provincia Pagos and register to start the process.

2) Complete the form with the corresponding personal and credit card information.

3) Print the payment receipt.

4) On arrival in Argentina, this printed receipt must be presented at Immigration Control. The receipt will be scanned by the Immigration officials, the information will be checked, and the traveller’s entry to the country registered.

http://www.argentinaindependent.com/currentaffairs/changes-to-payment-method-for-reciprocity-fee-visa/

confirmed by Argentina government web site

A past posted summary of the regulations and effect of the Reciprocity Fees:

Reciprocity Fees for Americans for specified arrivals now $US 160

US passport user reciprocity fees for arrivals just rose to $US 160, as of April 16, 2012:

http://www.migraciones.gov.ar/pdf_varios/tasas/Disposicion_845_2012.pdf

This is in response to recent US visa charge raise in US.

Increases also in Chile reciprocity fees for Santiago airport international arrivals, as well as visa charge increases in Brazil, Paraguay and Bolivia.

The trouble is that they keep changing the rules in Argentina to try to "reciprocate" the changes in Australia , Canada and the US. This is the reason for conflicting advice, even from different official Argentine agencies. It is often hard to keep the changes straight.

The actual regulations and changes are listed on this page, under Tasas de Reciprocidad.

http://www.migraciones.gov.ar/accesible/?tasas

The latest applicable to Australians on the list :

http://www.migraciones.gov.ar/pdf_varios/tasas/Disposicion_2379_2010.pdf

"1- Para nacionales australianos: el pago de la tasa será válido para múltiples

ingresos durante un plazo de UN (1) año desde la fecha del primer ingreso."

This latest measure means Australians do now get multiple entries for their $US 100 fee, but it only lasts one year from the first entry after payment, after which you need to pay again.

A later regulation changes it for Canadians, who now only get a single entry for their $US 75 fee. Canadians can now also have multiple entries for 5 years for $US 150.

(http://www.migraciones.gov.ar/pdf_varios/tasas/Disposicion_931_2011.pdf)

Americans still get multiple entries for 10 years (transferable to a new passport if you show your old one) for their

$US 160.

UNTIL JANUARY 7, 2013 - Since the question is continuously asked, let me repeat that the fees are ONLY payable for international air arrival at the two Buenos Airies airports UNTIL JANUARY 17,2013, NOT for international arrival by air at any other airport (such as Mendoza, Cordoba or Salta), and NOT to arrival by land, road or sea.

It does NOT have to be paid to exit from anywhere, as it is only an entry fee.