How to Redeem:
Log in to Guild Wars 2 with the account where you want to unlock gems.
Open the Black Lion Trading Company panel. The default hotkey is [O]. You can also click the lion icon in the upper left corner of the game screen.
Select the “Redeem Code” button in the upper left corner of the Store homepage.
Follow the on-screen instructions to redeem your serial code for gems.
How to check your balance:
No balance checker available
Abridged terms and conditions:
Gem card codes cannot be redeemed in-game (or on the site) for Guild Wars 2 accounts that were created on Steam.