SIM is also known as the smart card, the user identification card, GSM digital mobile phone must be installed on the card can be used. It stores a digital mobile phone customer information in a computer chip, phone book and other content encryption key and the user, for GSM network client identity identification, and the voice information is encrypted when customers call.

SIM card lock is mainly the number of PIN password input more than three times, and not correct, SIM card will automatically lock the. At this time, if you know the PUK password can be entered, will be able to unlock the correct SIM card. However, for most of SIM card users, they usually forget this password, or even do not know the password. So, how to SIM unlock the phone when it is being locked.

Please don't worry, for Samsung Galaxy S3/S4/S5/S6/S7 user, you can easily SIM unlock your Samsung phone in three steps by using the software which is named Android SIM Unlock.

Steps to SIM Unlock Samsung Galaxy S7/S6/S5/S4/S3

Step 1. Download, install and run the program on your PC, then enter the unlocking mode.
Step 2. Connect your Samsung phone to PC.
Step 3. Unlock your Samsung phone in a click.

Related Tutorial: How to unlock Samsung Galaxy S7 Edge/S7/S6/S6 Edge+/S6 Edge/S5/S4

Read the video guide here:


https://www.youtube.com/watch?v=uWv7CPYBjQw

There are many ways to unlock a phone and I sort the safe way to unlock mine, through permanent unlock service from Theunlockarena.com