SIM cards are always used on GSM phones; for CDMA phones, they are only needed for newer LTE-capable handsets.
SIM cards can also be used in satellite phones, computers, or cameras.
Questions on Stack Overflow are expected to relate to programming within the scope defined by the community. Your SIM has an IMSI, but only the operator does map that to an actual phone number.
Consider editing the question or leaving comments for improvement if you believe the question can be reworded to fit within the scope. A feasible route is this: You send an SMS or place a call to a defined endpoint.
This is good news for those who are new to unlocking.
Previously you would have had to connect your i Phone to i Tunes, and use the original SIM card and get a hold of country/carrier and SIM IDs to perform an unlock.
Follow the instructions on our Cydia page if you have not yet jailbroken your i Phone.
Follow these steps if you get an error message in SAM.
may disrupt the traditional SIM card ecosystem with the entrance of new players specializing in "digital" SIM card provisioning and other value-added services for mobile network operators.I SMS my personal phone from my work phone when I needed to do this.SAM is a jailbreak app for Cydia that allows you to unlock your i Phone so that you can activate and use a non-stock SIM card that is not supported by your existing carrier.This enpoint sees your number, and then notifies you back with your number.We have done this at a previous employer - we did not find another way. I re-read your original post, I mis-understood your question. I can go into my phone menu and look at my 'phone number' but i've changed the sim since and it now has a different number but the phone still shows the old number.. (smartphone) SMS message / voice call to somewhere is the only way I know of doing..