There could be a couple of reasons this is happening:
 
1. The billing address on your printmything account must must match the billing address on your credit card or the system will not accept your credit card.
 
2. The credit card number may not be entered correctly. Be sure when you enter the credit card number that you do not have any spaces or dashes in the number.
 
If, after confirming your credit card information is correct and your credit card is still not accepted, please call a Sales Rep at 888-281-0042 and they can help with your order over the phone.