International VoIP and traditional VoIP work in the same way. They also save you money in the same way:
VoIP makes your phone calls as local as possible.
Free International Calls
A few VoIP providers — especially those above — offer a free international calls or a number of free international minutes each month, usually 60 minutes.
Usually, these calls are to a specified number of countries/areas in those countries. Make sure you check before you call.
VoIP companies also sometimes place restrictions on these calls too.
That said, most VoIP providers meter their international rates. This means that they charge you a certain amount per minute.
The price depends on the VoIP provider and the telecommunications setup in the country you're calling. The price per minute for these international VoIP calls also varies from provider to provider.
Factors affecting International VoIP Calls
Several factors will make you pay more to complete your international voip call.
VoIP at the International Destination
If the country you're calling doesn't have VoIP phone service or if VoIP is illegal (it is, some places), you'll pay more to complete your international call.
In countries that do allow VoIP/have VoIP service available, you'll pay a very small amount to complete your call.
Countries that already have VoIP mean you'll pay less to call internationally.
Reliable Telephone Network for International Calls
Countries that have reliable telephone networks won't cost as much to call as countries without reliable telephone networks. It's fairly simple.
Some countries/locations have no telephone network. When calling these areas (for instance, Antartica) you'll have to pay to make a satellite call: that is, through the nose.
Mobile VoIP and International Calls
Another great way to save on international calls is with mobile VoIP. With a softphone on your computer or on your smartphone, you can make and receive calls from back home without having those callers calling internationally. Just make sure that you have 3G service or Wi-Fi enabled: then you can use VoIP to make those calls.
In addition, when traveling internationally, you may be able to set up a local number in the area you're traveling to. If callers can call locally, they'll avoid paying international rates.