When my card was bound, the authorization to debit $1 for the first time failed. When I tried again, it said Your card has been declined. Please try a different payment method. It couldn't be bound again. When I asked PayPal customer service, they said they didn't know the reason. It just said that the card issuer rejected it. I contacted the card issuer and said there was no problem with the card.
Paypal does not accept all cards so you may get the message the card is declined. If the Visa you are trying to add is virtual or issued online you may need to try another card.
Advice is voluntary. Kudos / Solution appreciated.
