How do You Use Your Google Play Gift Card Balance
Once you add or buy Google play gift card, it can be use to buy the Google play digital content.
Google play balance can be use within the one year of credit applied to your account.
But user may loss their credit due to inactivity on Google play account as they might not aware of the balance or validity of google play credit.
So you can check Google play gift card balance here http://onlinebalances.com/check-google-play-gift-card-balance.php anytime.