The iPhone is exclusively distributed by Globe Telecom for Philippine users. So the Smart Telecom users asked, “Can we use our Smart SIM with iPhone?” During the early release of iPhones, you can use your Smart SIM card by unlocking it. However, problems have been coming out such as problems on making calls.
Several users at the Macintosh Philippines forums said that making calls is suddenly not possible with iPhone using Smart SIM however there’s no problem in using the phone for text messages.
One user, William Yu, of It’s hip2b2 has successfully unlocked the iPhone for Smart Post Paid kit without using any software and supersims, that Smart users may use. He notes that users should use these tricks and cracks at their own risk. Please don’t proceed if you don’t know what you’re doing.