Square remembers your email address by credit card number. This was really surprising to me. I used Square once at a shop in Seattle, and had an email receipt

Square remembers your email address by credit card number. This was really surprising to me. I used Square once at a shop in Seattle, and had an email receipt sent to me. Almost a year later, I used Square back home in Toronto and asked for a receipt. To my surprise I didn't have to give any information: just using the same the credit card I swiped months earlier was enough.