Why am I receiving a CVN error when adding my debit card?
A CVN error can appear when the numbers you entered cannot be successfully verified with your card's issuing bank or if it is card type that Coinbase does not support.
To fix this error, be sure that you have entered your 16 digit card number, as well as the 3-4 digit security code on the back of your card correctly.
At this time, we can only accept Visa or MasterCard credit and debit cards with residential billing addresses. Discover, American Express, or prepaid cards of any type are not currently supported.