Visa extensions are generally easy to obtain without returning to your home country. The easiest is the temporary or tourist visa, which is valid for three months. You have two options for extending the visa: the first is to request an official one-time-only extension from the Dirección Nacional de Migraciones (National Immigration Office), which will require a renewal fee of AR$300 and be granted for another three-month period; the second is to exit the country. The latter can be done as simply as taking a ferry across the Rio de la Plata into Uruguay and returning that same day. This practice of “renewing” visas has been tolerated by immigration officials, although some tourists with several years of stamps in their passports have been known to receive warnings and “final extensions” of their visas.
To update the longer-duration temporary visas, most of which are valid for one year, you have to apply for an extension in person at the National Immigration Office. These extensions are granted upon the discretion of the Office. An extension of a work visa will depend upon your work contract stipulations, and the extension must be initially requested by your Argentine employer. Likewise, a student visa renewal will require sponsorship and proof of continuing enrollment from the school where you are studying. All temporary-residence visas can be renewed twice for a maximum validity of three years.
The National Immigration Office is located at Av. Antártida Argentina 1355 in Retiro, phone 4317-0200. Appointments are not necessary to request an extension, but expect to wait at least one to two hours to meet with an immigration official. Extensions are handled between the hours of 8:00am and 2:00pm. The deadlines for extensions vary depending on your country of origin, so be sure to obtain specific extension information when you are issued your initial visa.