If you're credit/debit card is being rejected by PayPal with the message "The card you entered cannot be used for this payment. Please enter a different credit or debit card number." it might be due to one of the following reasons:
1. Credit Card Is Linked or Associated with a PayPal Account.
If you’re using a credit card that’s linked or assigned to a PayPal account, try login to PayPal during payment process. You can change the source of fund to make the payment after logged in to use credit card instead of PayPal balance.
2. Credit Card Is Previously Used in PayPal Account or Assigned in Closed PayPal Account
PayPal remembers a credit card details even when it’s already been removed from the account. The information also been remembered even if PayPal account which linked to the credit card is closed and deleted. In this case, try another credit card, or assigned the credit card to a PayPal account, and pay with account logged in.
3. PayPal Limit on Non-Member Credit Card Usage
According to PayPal source, there is a limit based on the number of times, the amount of the transactions, the type of merchandise being sold that a credit card can be used within the system without having to verify ownership by opening an account. The restriction is for security and fraud protection reasons. There is no workaround to this limitation, but you should be able to use another credit card. If there is problem, try using another email address. Else, register an PayPal account.
4. Credit Card or Email Address Raises Flag in the Transaction
Closely link to reasons above, where some part of the transaction raises flag on the server that stop the payment. Two possible flags are on credit card or email address. Try changing either credit card or e-mail address or both when attempting to pay again.Please contact firstname.lastname@example.org if you have any additional questions.