You may activate personal identification number (PIN) protection on your SIM card through the Settings menu of your mobile device. Once activated, you will have to enter your PIN before you can use mobile services on your device.
All GigSky SIMs have the same PIN, 12345678, but we ship all our SIM cards with PIN protection turned OFF. In normal operation, you will never have to enter the PIN.
The personal unlocking key (PUK) is used to unlock a PIN-locked SIM card. If the wrong PIN is entered more than three times in a row, the SIM card will be locked. You can unlock your SIM card by entering the PUK assigned to that card. If the wrong PUK is entered ten times in a row, the SIM card will locked permanently, and the SIM card will have to be replaced.
Carrier locked devices
This Wikipedia page has background information on Carrier Locking, also referred to as SIM Locking: https://en.wikipedia.org/wiki/SIM_lock
Typically, a locked handset will display a message if a GigSky SIM is inserted.
You may see a screen with the heading “SIM Not Valid” or “SIM Not Supported”.
On Android smartphones:
The phone will display a message saying “SIM network unlock PIN” or “Enter Network Lock Control Key” if network locked. This use of “SIM” and “PIN” can cause confusion with the SIM PIN described above. The “SIM network unlock PIN”, required to unlock the device to use third-party SIM cards, is not the same as the “SIM PIN”, used to lock and unlock the SIM card.
May display different messages such as "Enter special code" or "Enter unlocking code", or in some cases the handset will simply display a message stating that it is locked.
In all cases, if your device is carrier locked, you should contact the supplier to get it unlocked.
The U.S. carriers Sprint and Verizon operate CDMA networks in the United States. They allow their customers to use SIM cards from other operators when traveling OUTSIDE the United States. This is sometimes referred to as International SIM Unlock. However, the device will not accept a SIM card from a US carrier other than the original provider unless it is FULLY unlocked.
An International SIM Unlocked device will NOT work with a GigSky SIM card.