The service is offered free of charge, but airtime is deducted from your plan if you decide to place a call on hold. If you are outside your local calling area, long-distance or roaming charges will apply.
If I receive a call when I'm already on the phone, will the number of the waiting caller be displayed?
Yes. If you have signed up for call display, a message indicating the second caller's number will be displayed on the screen of your mobile. If that caller is in your saved list of contacts, his or her name will also be displayed.