Can I use a Canadian Google Play gift card on an American account and vice versa? Can I use a Canadian Google Play gift card on an American account and vice versa?
NO, as per Google Play balance restrictions:


Can only be used for purchases on Google Play.
Can only be used to purchase or rent content sold in the same currency.



  If you redeemed an Australian Google Play gift card or promotional
  code and then travel to Germany, you won't be able to redeem your
  Google Play balance since paid content in Germany is sold in Euros.



Google Play balance can't be used to purchase devices on Google Play. Google Play balance can be used to pay for subscriptions on Google Play Music and Google Play Newsstand but can't be used to pay for other types of subscriptions.