Hi Support, When the applepay express transit option is used on emv payment cards, like this iPhone - Open “Settings” → “Wallet & Apple Pay” → “Express Transit Card”. And a emv single card has been enabled under Express Transit And on transit reader Apple Enhanced contactless Polling support is provided, ( with VAS not supported, user authentciation not supported) Sometimes ATQB response also comes from the iPhone or iWatch instead of the ATQA response, and then it causes the transit reader to report as collision error in the polling. Sequence of the packets: WUPA WUPB ECP frame WUPA WUPB ATQB WUPA ATQA