Automatic Teller Machines - ATMs
ATMs usually close at 10.00 or 10.30 pm so if you plan to go out partying you'll also need to plan how much to take. However, you may find ATMs working after 10.00 pm in secure areas like shopping centres but don’t count on it. The reason for this is security. If the ATM is not functioning a thief can not hold a gun to you and demand you withdraw all your money from the machine.
When withdrawing money you will get a mix of notes. For example if you withdrew $R200 you would most likely receive 150 in 50's and the remainder in 10's. The daily limit on withdrawals depends on your bank but work off a value of around $R800 to $R1000 per day. At night the maximum withdrawal is R$500 but I do not know what time it is that ATMs switch to this lower limit. 7pm perhaps?
Using an ATM on the street increases your risk of unwanted attention so a better idea is to go to a shopping mall and use an ATM inside the centre. Typically a bank branch or shopping mall will have several ATMs but only one or two of these will carry the Cirrus Maestro or Visa Plus symbols. Obviously you will need to use these ATMs. On these machines you should be given a choice of languages which is an added bonus for those not familiar with Portuguese. I've created a little page with link here common banking vocabulary should need it.
A common area of concern amongst travellers is knowing in advance if they will be able to withdraw money at their destination. The best safe guard against finding yourself unable to withdraw cash is to carry two different cards. Your everyday bank card (with a cirrus maestro or visa plus facility) and a credit card. Between these two cards you should be able to withdraw money from most locations.
To further allay your fears you can check in advance as to where the nearest ATM that accepts your card is.
The Cirrus Maestro site has a feature to locate ATMs that operate 24hr/day but I wouldn't rely on this in Brazil.
One final point to note is that in the lead up to and during Carnival the ATMs can run low or out of cash completely. This is a result of the tens of thousands of tourists, both local and international who arrive in Carnival hotspots like Rio and Salvador and head straight to the bank to get their spending money. Cash just drains out of the ATMs. During Carnival most companies close up shop so no one is around to fill up the ATMs. Make sure you have enough cash before you start.