Interpreting AVS and CVV code responses

[Will]

Been digging into the fraud-prevention issue a little. Trying to come up with guidelines for our order fulfillment folks to flag potential fraudulent transactions.

I turned our gateway live and did a couple real transactions with credit cards to see what legitimate reponses looked like.

We're using Payflow Pro and we get them back like this:

AVS: Match (Y)
CVV: Unknown (Y)

I assume the AVS: Match (Y) indicates a good situation. I know the CVV code we entered is correct, but the Unknown (Y) response confuses me.

When we've been in test mode, entering the 4111111111111111 test number we've also received:

AVS: Partial Match (Z)
CVV: Unknown ()

What's the difference between "CVV: Unknown (Y)" and "CVV: Unknown ()"

I'm trying to figure out what responses our fulfillment folks need to watch for with the AVS and CVV codes -- aside from billing/shipping addresses matching.

Can anyone point me to a resource for this?

Thanks.

[Will]

From PayPal's documentation, PayPal PayFlow Pro response codes are:

AVS address response codes
Y = Match
N = No match
X = Cardholder's issuing bank does not support this service

AVS zip response codes
Y = Match
N = No match
X = Cardholder's issuing bank does not support this service

CVV2 response codes
Y = Match
N = No match
X = Cardholder's issuing bank does not support this service

How do these translate into the reponses we're seeing in the order summary under "Payment"?

Does AVS: Match (Y) mean both address and zip match and AVS: Partial Match (Z) means only one of them matched?

If we see CVV: Unknown (Y) does this mean it's a good match?

Thanks.

[jmestep]

AVS Y -- both match
AVS Z zip matches
AVS A - numbers in street address match

I don't know about the CVV

[AbleMods]

Perhaps this will help better...


Address information is
...not provided for AVS Check (B)
...AVS Error (E)
...Non US Card Issuing Bank (G)
...Retry, system is unavailable (R)
...AVS is not supported by card issuing bank (S)
...Address information for cardholder is unavailable (U)

Street Address Matches AND
...First 5 digits of Zip Code Match (Y)
...First 5 digits of ZIP Code Do NOT Match (A)

Street Address Does Not Match AND
...9 digits of Zip Code Match (W)
...First 5 digits of Zip Code Match (Z)
...First 5 digits of ZIP Code Do NOT Match (N)