When testing specific error codes in sandbox we have found an issue where certain responses are incorrect if using a 0.00 amount.

An example is using zip code 46201 which should return AVS response "A".

With a 0.00 amount it returns AVS response "N", but anything greater than 0.00 it correctly returns AVS response "A".

This will be a problem for us as we are only pre-authorizing the card to validate CVV and AVS responses and do not wish to authorize any amount from our end.