We recently reconfigured our site and no longer require billing address when placing an order. Almost all orders can be successfully processed without a billing zip code.
We've identified an issue where a small number of customers' banks are declining these transactions because the card issuing bank is not seeing a matching billing zip code on the order.
If you think you may be affected by this issue you can call us at (877) 862-0222 to place your order.
This issue is only affecting a small number of card issuing banks so you should also be able to place your order by using a different card.
We apologize for this inconvenience and are working on a solution to this issue.