Toronto's TTC transit system, the fourth largest in North America, may eventually support Apple Pay for fare payments.

A rough mockup of the PRESTO card in Apple's Wallet app

Metrolinx, the transit agency that manages integration of the PRESTO card system in the Greater Toronto Area, recently detailed plans to support mobile payments within the coming years, according to the Toronto Star

Apple contacted Metrolinx last Wednesday to set up a related meeting, the agency said. The report suggests there are a few compatibility issues between the PRESTO system and Apple Pay that would need to be resolved. For that reason, Metrolinx's rollout of mobile payments may start with Android smartphones.

Apple Pay support would enable commuters to hold a compatible iPhone or Apple Watch near a PRESTO card reader to pay their fare on streetcars, buses, and at turnstiles in subway stations throughout the TTC system. Mobile payments could extend to other Canadian cities with PRESTO like Hamilton and Ottawa.

The process is similar to using Apple Pay for in-store payments. Depending on the iPhone, that means double-pressing the home button or side button, authenticating with Touch ID or Face ID, and holding the device near the card reader. Apple Watch payments are also activated by double-pressing the side button.

Toronto would join a handful of cities with transit systems that already support Apple Pay, including Chicago, Portland, and Salt Lake City in the United States, Beijing and Shanghai in China, and other global cities like London and Tokyo.

Metrolinx said there is no firm timeline as to when the TTC will begin accepting mobile payments, but it sounds like a multi-year process.

(Thanks, Pedro!)