If your 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:
- Your card is associated with a specific PayPal account, and you're not logging in with that particular account.
- Your card associated with a PayPal account has been closed.
- You've linked the card to a PayPal account, but have not yet confirmed it.
- You've exceeded your card limit with the PayPal system.
- Your email address is raising a red flag in PayPal's system.
- Your browser is not accepting cookies.
- You should clear any existing cookies and try again.