As long as your telco subscription plan includes free incoming calls when using the Callback method, the answer is no. Or, if you have a data plan or connected to WiFi when using the Internet Call, you will only be using Hoiio credits.
Take note that even if you have free incoming calls, the telco charges for roaming if you receive incoming calls overseas. Callback method uses incoming call. Hence, we strongly advise not to use Callback when overseas.
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