Doing it through banking or credit card infra sounds handy. The site gives me a magic number and also sends it to their bank. I give the magic number to my ba

Doing it through banking or credit card infra sounds handy. The site gives me a magic number and also sends it to their bank. I give the magic number to my bank and the two banks agree I am old enough without telling their respective customers (or each other) who is asking and who is responding?