There are two types of calls that you can make in Yolla.

The first one is a free Yolla-to-Yolla call. These calls are made between Yolla users. So, in this case, both subscribers need to have Yolla installed on their devices. This call is free of charge (only data charges from your cellular operator may be applied if you use a cellular connection).

The second type of call is a paid call. In this case, the person that receive the call doesn’t need to have Yolla installed on their device. They will receive an ordinary call to their landline/mobile number.
Yolla will only charge you according to the stated rate in the Yolla app. The other person is charged local rates for incoming calls. In most cases, local incoming calls are free of charge.