A subsidy unlock code refers to a code to unlock the unit for another carrier.
LG is a 3rd party contract manufacturer that makes the cell phone for a specific carrier.
To un-lock the phone from the carrier, you need their permission.
For most carriers you need to:
Have the phone paid off.
Have the account paid up to date.
Have the phone for about 6 months.
Note: Each carrier is different and may have different requirements.
For additional information, please contact your carrier.