If you have the PRESTO app, you can check your balance by logging in to the app, swiping right until you see the grey PRESTO image and selecting "Check Balance".
Check your balance at PRESTO vending machines at TTC subway stations, OC Transpo stations, GO Transit stations and UP Express stations.
Check your balance in person at a Customer Service Outlet or Shoppers Drug Mart location.
Log in to your My PRESTO Account and you will see your balance on the main page. Your online balance can take up to 24 hours to update after you take transit or load your card.