Voice over Internet Protocol, or VoIP, is a technology by which telephone calls are placed over the Internet rather over the standard Public Switched Telephone Network (PSTN), also known as the landline network. For a detailed explanation of how to use VoIP and the technology behind it, read our article How VoIP Works.
Making an international call from a VoIP telephone line requires the same dialing format as a landline phone: international dialing prefix + country code + area code + local number. Depending on the VoIP telephone service you use, you can either make calls using a regular telephone connected to a VoIP router or directly through your computer using a headset microphone.
Making an international call with VoIP can be cheaper than using a landline phone. International calls using VoIP can be as cheap as two cents a minute to certain countries. But the biggest advantages of making international calls using VoIP is that you can choose to purchase a phone number in another country.
Let's say you live in the United States, but all your relatives live in England. VoIP calling services like Vonage and Skype can assign you a British telephone number, even if your phone is in the United States. That way, every time you call your relatives in England, it's charged as a local call, not an international call. The same goes for your British relatives. Depending on their local calling plan, they might be able to phone you for free.
VoIP calling plans are either subscription-based or pay-as-you-go. Vonage uses the subscription model. Vonage users pay a flat rate each month for a certain amount of minutes. That rate doesn't include international calls. Those calls are charged separately at rates that vary with each country.
Skype, another popular VoIP service, does not charge a monthly fee, but charges for each call made. Skype users load money into their account using a credit card or PayPal, and money is subtracted from the account each time they make a call. Naturally, international rates are higher than local rates, but still much cheaper than a landline phone.
On both Vonage and Skype, calls made from one subscriber to another subscriber are free, even for international calls. So if your family in England has Vonage and you have Vonage, you can talk to each other as long as you want for free.
Now let's talk about making an international call from a cell phone.