Google Wallet is replacing Google Pay. The main difference between the two apps is Wallet allows you to load a cash balance as well as emulate your credit/debit/loyalty/boarding cards. Google Pay was accepted in any shop that accepts contactless card payments. I used Google Pay, with my Wise card, at 711, Lotus's, Big C and Bangrak (Esso) but I haven't upgraded to Wallet yet so I don't know if the cash side of it can be used in the same way. This is the question the OP asked. He didn't ask if cash or credit card is best!