Please Pay attention to Rain Service Details:
The direction of this service is from Iran to outside, so you can not call Iran using this service, but you will have a number inside Iran and you can receive calls from Iran if anyone call that number in Iran.
There is no expiration for your credit.
There is no hidden fee, no connection fee, no extra fee.
There is 1-minute rounding.
Rates to receive calls from Iran is 1.9 Cent/Min.