Once you arrive in Brasilia and you want to call your home country you will realize that this can be a rather frustrating experience. Brazil has several mobile phone networks operators and each of them has a different phone operator code.
To call a foreign country from Brazil you must dial the following:
00 (exit code) + your Brazilian operator code (see list below) + the country code + the phone number (dropping the first 0).
Example from Brazil to Australia: 00 15 61 2 xxx xxx
00 is the Brazilian exit code 15 is the operator code (see below) 61 is the Australian country code 2 is the area code for Sydney
List of Brazilian operator codes:
Vivo: 15
Claro / NET / Embratel: 21
Oi: 31 (14 in the Southern region)
TIM: 41
CTBC / Algar: 12
Sercomtel: 43
Nextel: 99
Other cheap ways to call home: if your call recipient has WhatsApp (very commonly used in Brazil), you can use the phone or video chat buttons on the top right of the screen. If you are calling a business or a land line, you can use Skype for free for quite a while, then you can buy an unlimited monthly package for less than $4/mo. This is useful if, for example, you have to call a government agency and they put you on hold for an hour!