The feature of calls using Alfa4you SIM card is that they are implemented by utilising a callback service, significantly reducing the cost of international calls.
For the user, the difference is that after dialling the call recipient's number and pressing "Call" button, the connection does not occur immediately – the client sees the message "Wait for call" on the screen of the mobile phone, and within seconds receives an incoming call, connecting the client with the intended recipient.
A detailed algorithm for the call is as follows:
 1. Dial the symbol "+" or "00" (the international format).
 2. Enter the call recipient's number with the country code.
 3. When calling to landlines, you must also specify the city code.
 4. Press the "Call" button.
 5. The screen displays the message "Wait for call".
 6. Answer an incoming call, which will occur in a few seconds, by pressing the "Answer" button. 

After brief information about the current status of your Alfa4you SIM card's balance, a connection with the call recipient will occur.