[beambot]

Last time I implemented a CC regex, it was a little more involved than just removing empty spaces. So you see... Your trite example fails to pass muster just as well. (Anymore, I'd just use one of many Stripe libraries... no fuss, no muss.)

[weaksauce]

really though, it's not that hard to write a simple regex or few line replace command to make the form dead simple to use. creditCardString.replace(" ", "").replace("-","").replace(etc...)

or, if you can use a regex in a sane language replace("[^0-9]", "") then check for the length of the credit cards that you are using. shouldn't take a dev more than 5 min to code and test. Your argument is not really all that valid.

[nucleardog]

That's exactly what I do whenever I expect a number like this. For instance, phone numbers... Normalize them by replacing all non-numeric characters /then/ validate them. I can't imagine trying to validate the hundred different formatting variations for phone numbers.