As the credit card industry has moved to using chip cards, the criminals have moved to targeting online stores since the brick and mortar targets now make it harder to use fraudulent credit cards.
Because of the high level of fraudulent credit card attempts and the various tactics used, we have to set our fraud filters to be very strict. If you are having problems getting your credit card to process, please make sure that you have entered your billing and/or shipping address exactly as it is on file with your credit card company. If, after verifying your address is being entered exactly as it appears on your credit card statement, our system is still denying your payments, we recommend you call your credit card issuer. Typically they can tell you exactly why their system responded with an "N" for AVS match.
We apologize for any inconvenience and thank you for your understanding our desire to reduce losses due to fraudulent purchases.
This keeps prices lower for customers, and helps us ship more orders, so you can be flying.