T-Money cards have a weak NFC Signal by design. In order to use the T-Money App successfully, you need to put your card on the phone’s NFC antenna, and move slowly until the phone can detect the card. On some devices, sometimes after you have successfully read the first card, you may need to reset the NFC by turning it off and on again, before you can read the second time. We are checking to see how to improve this.
We have tested the old T-Money Cards, new T-Money Cards (One Card All Pass), Seoul City Pass+, and M Pass. Our app can support all these cards, but if your phone’s NFC antenna is not strong enough, you may have difficulties to read the card, and you may need to try a few times.
For certain newer Samsung devices, the NFC antenna is embedded on the original Samsung NFC battery. You can see “Near Field Communication” on the battery. If you are using 3rd party batteries, NFC may not work.