Can I install the service in a phone with two SIM card slots?

If you have a phone with two SIM card slots, the NFC-enabled SIM card in which the service can be installed must be placed in slot 1. Similarly, while using the service, the SIM card must remain in slot 1. You can use slot 2 with another SIM card. This clarification does not apply to users who have a phone with the secure element integrated into the phone (see the list of affected Samsungs).

For more information about NFC SIM card compatibility, you can visit this page.