As long as you're within two hours from your first tap, you won't be charged another fare. If you are on a vehicle or enter a station with a few minutes remaining on your transfer, you can continue to complete your journey and do not need to tap if the transfer expires while you are on that vehicle.

On the Toronto Transit Commission (TTC) system, the rule for "tapping" depends on which mode of transport you are using and whether you are transferring. If you are using a PRESTO card, credit card, or mobile wallet, you must tap once when you enter a subway station or board a bus or streetcar. You do not need to tap off when you exit. If you are transferring between two different TTC vehicles (e.g., from a bus to the subway) within a two-hour window, you must tap your card again on the second vehicle or at the subway turnstile. The system will recognize your first tap and will not charge you a second fare, effectively acting as your "transfer." However, there is one major exception: if you are transferring to a GO Transit train or a different regional system (like MiWay or YRT), you must tap off your previous vehicle and tap on the new one, as these systems use different fare structures. For a standard trip entirely within the TTC network, the "tap on only" rule is the standard for buses, streetcars, and the subway.