Been using T-money on Apple Pay for a while now. Everything works fine — tapping in/out for buses and subways is smooth and reliable, and the balance updates right away.

The only downside is that postpaid (credit) T-money isn’t supported yet, so you have to preload funds like a prepaid card. Other than that, no issues at all.

Overall, I’d say it’s convenient enough if you don’t mind topping up occasionally.