U.S. cards just have the card number, which of course is separate from the account number, and then there's the "security code" on the back, which is typically a 3 or 4 digit number. But there is no other account information printed on the card.

Also, I found out when I began working for international clients, the U.S. doesn't participate in the IBAN system. Instead we have something else which necessitates international wire transfer payments be made via an account number, a routing number, and a swift number. It's very annoying. (perhaps business accounts work differently, I get paid directly into my personal account which I'm sure is a bad idea, but it works for me).

> But it seems to me that buying stuff with a debit card isn't that common in USA.

No it is, almost all my purchases are via debit but it comes off my credit card. Most banks come with Credit cards that are just a fee-less low-liability proxy for debit that gets withdrawn from the bank account.

You can usually work out the IBAN from bank name + sort code + account number.