Replace your SIM card with one from a different network operator. If your device connects to the new network, and you are able to make calls or browse the Internet, then your device is unlocked and ready to use with a GigSky Data SIM card. However, if your device displays an error message, such as 'Invalid SIM' or 'SIM Locked', then this means that your device is most likely locked. It will need to be unlocked to work with a GigSky Data SIM card.
For example, with an Apple iPhone, you may see the following message after inserting a GigSky SIM card:
"The SIM card that you currently have installed in this iPhone is from a carrier that is not supported under the activation policy that is currently assigned by the activation server. This is not a hardware issue with the iPhone. Please insert another SIM card from a supported carrier or request that this iPhone be unlocked by your carrier. Please contact Apple for more information."
This message indicates that the phone is still locked. If you see this, you should contact Apple Support to verify that the phone shows as unlocked on their activation server. No matter what your former carrier may say, if the phone is flagged as locked on Apple's activation server, it will not be able to use any third-party SIM card, including a GigSky SIM.
To unlock your device, contact the company from which you bought it. You may be charged for the unlocking process, if your device is still under contract to a mobile carrier.