Actually, you can just do a Luhn check on the credit card and if it fails show an error message. Scammer cards will pass the Luhn check, so it won't be helpful

Actually, you can just do a Luhn check on the credit card and if it fails show an error message. Scammer cards will pass the Luhn check, so it won't be helpful for them validating cards. But it will catch many customer typos, thus giving them immediate feedback.