Great article and documentation of the process, this is very important to learn and to understand the project’s decisions.
Recently I was talking with friends about how frustrating is to start a payment flow: put the credit card information, and then realizing that you inserted the credit card number in the wrong field. Every time that I do it, first I hate myself, then I blame the designer.
The credit card is different in US than in the rest of the world, the name on card comes first than the numbers?
It’s a simple thing that does all the difference for me as a user. The order on the card should be followed on the screen.
About the Zip Code,I get it all the security thing, but when you put it you’re limiting your client, don’t you’re?
Probably — and I hope so — you verified all the transactions and none was from a non-US credit card, but you don’t know if tomorrow one of your clients will send an invoice for another country. Just keep this in mind for the future!
In Brazil to increase security they ask a document number as CPF (social security number here) or Passport number.
Don´t forget to write a part II telling about the user testing and metrics after the launch! ;)