The currency conversions provided were correct at press time. Rates fluctuate, however, so before you depart, consult a currency exchange website such as www.xe.com for up-to-the-minute rates.
The peso is the main unit of currency in Argentina. It is indicated with the symbol "$" and is divided into 100 centavos. (Prices quoted in U.S. dollars are often accompanied by the symbol "US$" or "$US.") Centavo coins come in denominations of 1, 2, 5, 10, 25, and 50. There are also 1- and 2-peso coins; the latter are generally intended as commemorative collector coins but can also be used as currency. Paper money comes in 2-, 5-, 10-, 20-, 50-, and 100-peso bills. The alleged Argentine coin shortages that made media headlines around the world were actually a false, politically motivated rumor. It's true that shopkeepers are hesitant to give change unless you buy something, as they are in cities across the world. Do not accept torn or taped bills with a value over 10 pesos; as a foreigner, you are more likely to have these bills passed off on you by shopkeepers, and they may be difficult to use later.
It's a good idea to exchange at least some money -- just enough to cover airport incidentals and transportation to your hotel -- at your local American Express, Thomas Cook, or bank before you leave home (though don't expect the exchange rate to be ideal), so you can avoid lines at airport ATMs. If there's no bank with currency-exchange services close by, American Express (tel. 800/807-6233; www.americanexpress.com) will ship traveler's checks and foreign currency, though, with a $15 order fee and additional shipping costs. At Ezeiza, there's an ATM at the Banco de la Nación just outside of the arrival terminal.
U.S. dollars are no longer as widely accepted in Buenos Aires as they were before and immediately after the December 2001 peso crisis. However, you can still use them to pay in some business-class hotels, and at restaurants and businesses catering to tourists. For the vast majority of your purchases, however, you will need pesos. You can exchange money at the airport, in hotels, in casas de cambio (money-exchange houses), and in some banks. The huge American Express building is next to Plaza San Martín, at Arenales 707 (tel. 11/4310-3000). In addition to card-member services, the bank offers currency exchange (dollars only), money orders, check cashing, and refunds. You can also withdraw pesos at ATMs, which are plentiful in Buenos Aires, but use only those in secure, well-lit locations. Even if your bank allows you to make larger daily withdrawals, Argentine ATMs generally only give out pesos in the value range US$100 to $250 maximum at a time or on a daily basis, so plan accordingly. It will be hard to break large bills usually dispensed by ATMs; withdraw money in uneven amounts so that a portion comes in small bills. You can withdraw cash advances from your credit cards at banks or ATMs, but high fees make this a pricey way to get cash. Keep in mind that you'll pay interest from the moment of your withdrawal, even if you pay your monthly bills on time. You can have money wired to Western Union, Carlos Pellegrini (9 de Julio) 1365 at Arroyo (tel. 0800/800-3030 or 11/4323-4200). Be aware that in 2011, a law was passed in Buenos Aires banning the use or possession of a cellphone while banking, which in theory prevents bank robbers from communicating with each other. You will be asked to leave your cellphone in a locker or with a guard when in a bank.
It is sometimes difficult to exchange traveler's checks outside of Buenos Aires, so plan ahead and bring a sufficient amount of pesos on day trips.
Visa, American Express, and MasterCard are accepted at most establishments in Buenos Aires. Also, note that many banks now assess a 1% to 3% "transaction fee" on all charges you incur abroad (whether you're using the local currency or your native currency). Many places in Buenos Aires will also charge a fee when you use a credit card, often ranging from 3% to 5%, in addition to anything your bank will charge.
For help with currency conversions, tip calculations, and more, download Frommer's convenient Travel Tools app for your mobile device. Go to http://www.frommers.com/go/mobile and click on the Travel Tools icon.