Banks are not as plentiful as they are in New York and ATM’s are only located within the banks. In the residential sections like Palermo and Recoleta Banks are extremely hard to find and are limited to the major streets, so it is best to prepare for this factor before going out.
The Argentine government limits the transactions of foreigners, which generally never exceeds 1000 pesos for one transaction. These transactions can be costly because of your local bank so make sure to check your rates for withdrawal before you leave home. Also, you need to tell your bank that you will be abroad so they do not think your account has fraudulent activity and freeze it!
The ATM sections of the banks are open 24 hour a day, 7 days a week, but the banks themselves are only open during the week from 10 am to 3 pm.
Some students come with them as backup for their cash and credit cards. Do not rely on them as they are very hard to use in Buenos Aires and South America. The advantage is that if you lose them, or if they get stolen, you can put in a claim for your money.
Only the major restaurants and shops take credit cards. Most transactions made are usually in hard currency.