Hi all,

I am in the process of setting up a credit card payment interface. From a technical point of view everything is working fine and I am successfully using the providers test gateway (currently testing eWay but no final decision has been made).

The topic I wanted to start though is the question, how much feedback to you provide to the user in case something goes wrong with the payment. Going "wrong" can mean various things here:

1) My program crashed (shouldn't happen, of course)
2) User accidentally entered wrong values (e.g. wrong number of digits, expiry date, etc.)
3) User intentionally enters "wrong" values (fraud,"testing",etc.)
4) The payment gateway (e.g. eWay) is not available (HTTP status not 200)
5) The payment gateway (e.g. eWay) complains about a format error
6) The merchant bank responded with an error

Let's consider some "interesting" scenarios as food for thought.

a) what user feedback would you provide if the merchant bank says "Insufficient Funds" or "Stolen Card"?
b) do you distinguish between different merchant bank errors like "Invalid Card Number" and "Card Stolen"?
c) do you check, whether a user gets the card number wrong again and again?
d) what do you tell the user, if the payment gateway (e.g. eWay) is not available?
e) many more scenarios possible...

There you go... hoping for your replies...

Markus

Spoken like a programmer

If your 100% on the errror you should pass it on, though if you get a `stolen card` I would suggest something like `Please Contact the Card Issuer`.

I would give the client the message `Invalid Card Number` for the other see a)

There is a way to verify the Card Number before it goes eWay, I would try that first.

`Temporary Error: We were unable to verify your Card` you may wish to try a little later.

Some banks might not let you say "stolen card" etc online so check your T&C before even thinking about that one. This is generally a bad idea anyway as you'll get people on your website testing card numbers unless you've got some login front-screen page.

There's 4 scenarios to think about:
1) Payment went through successfully - advise customer
2) Payment was declined by 'someone' - try to distinguish between a retryable decline (e.g. bank error) and a permanent decline (e.g. card stolen) and advise to try again later, or to check their card details.
3) Payment failed & you safely know the transaction didn't go through - say try again later.
4) Payment failed & your app doesn't know the status of the transaction - say to call your customer centre.