How do Viber Out credits work?

Question

Is the Viber out credit a fixed amount plan for unlimited calls or charged per call?

Answer 1

Viber Out credit is not a fixed amount plan for unlimited calls. Once you purchased the Viber Out credit, you can make calls to any phone numbers ((landline or mobile) to any destination around the world using the credit until it runs out.

You have to just add more credit, to make more calls.