Coverage follows the cities, and the cities are far apart
Buenos Aires, Santiago, Lima, Bogota and the Brazilian coastal cities have coverage that would not embarrass a European capital. The Andes, the Amazon basin, Patagonia and the long bus routes between them do not, and no travel plan changes that.
Plan for offline. Download the map, download the ticket, screenshot the address. This is advice we would give regardless of what you buy from anyone.
Borders are frequent and roaming between them is not free
There is no continental agreement here equivalent to the European one. Crossing from Argentina into Chile or from Peru into Bolivia means leaving one operator behind and entering another commercial relationship.
For a single country trip, buying locally is usually both cheap and easy. For the classic multi country route, the repeated purchases and the wasted balances add up faster than the price difference suggests.
Brazil is not the rest of the continent
Brazil is large enough, and different enough, to be treated as its own market rather than as a part of South America. The language is different, the search vocabulary is different, and the destination set Brazilian travellers care about is mostly Argentina, Chile, Uruguay and Peru rather than Europe.
If you are Brazilian and reading this in English, the page written for your market will be more useful than this one once it is live.
How to decide
One country for two weeks or less, buy a country plan. Two or more countries, or a route that includes long overland legs, take the regional option and stop buying at borders.
Either way, treat coverage as a planning constraint rather than a product feature. The gaps here are real and they are the same gaps for everyone.
Where are you going?
DestinationsCommon questions
Is there free roaming between South American countries?
No. There is no equivalent of the European agreement. Each border is a new commercial relationship.
Will I have signal in Patagonia or the Amazon?
Frequently not, for any operator. Plan offline for both, and treat any signal you do find as a bonus.
Is Brazil covered by a South America plan?
Usually yes on paper. But Brazilian travellers search differently and want a different destination set, which is why we treat Brazil as its own market rather than a subsection of this one.
Should I buy locally instead?
For a single country, very likely. For a multi country route, the repeated purchases and stranded balances usually cost more than they save.