Question: Why is my credit card not be accepted?
Answer: Almost all rejections are do to AVS (Address Verification System), the service that compares numbers in the ZIP code and address fields with those on record for the cardholder's billing address, is only available in the US.
Make sure your billing address matches your credit card's billing info.
Countries outside the US - Things you can do:
Use Paypal for check-out
Call your credit card company and see if you can get your card AVS ready for US purchases.
Question: I received an error message concerning my credit card information during check-out, did my order go through?
Answer: If you have received an e-mail order confirmation of your order, then despite the error message that you received your credit card was processed.