I have family members traveling through the following countries over the next couple of weeks:
Considering that they're spending 4-6 days in each country, they want to have a phone in hand to be able to contact family back home, and more importantly, to have a phone for emergencies.
Do they have to get a pre-paid SIM card in each country that they go to? Is there one that will work in multiple countries?
Aside from the onesim mentioned above, there is no carrier I am aware of in South America which covers all of those places without incurring roaming charges. Movistar is in all of those places, Claro may be as well, but when you register for the SIM, you incur roaming charges once you move to the next country. A few years ago, getting a SIM in each country would have been my recommendation, as they were easily purchased from any kiosko for small cash and no questions. Lately, anti-terrorism efforts have encouraged more documentation when purchasing SIM cards. Argentina in particular was a headache for me, since I didn't have a national ID card, I had to go their main office instead of one of their many branches.
Most US carriers have travel plans you can turn on and off which allow reduced roaming fees and small amounts of data for global ready devices. I think T-Mobile has a very generous international roaming plan. I've used Verizon and whenever I'm about to leave, I have them turn the travel plan on for a month. When I return, they turn it off. I think it's about $30 depending on the tier. I use it as an emergency phone since texts and calls are still expensive and I almost always go through the process of getting a SIM wherever I go. (I actually have a framed collection which hangs on my office wall, they're neat little mementos.)
Basically, there are several okay solutions but surprisingly few great, affordable solutions. I hope this helps.
I've used http://www.onesimcard.com/ in Mexico (supposedly it works in more than 200 countries), but I can't recommend it 100%. It can be difficult to use, and the calls and SMSes often failed. But of course it's better than nothing! I would recommend getting OneSimCard as a backup, but then trying to pick up a cheap SIM card in each country as a primary means of communications.
I use SIM2Go all over the world, and find their conditions better than the others offering similar product: among other things, the cards never run out as long as you use them at least once every six months. Go to their website.
