DoDirectPayment API call failed. Error Code: 15005

Any time you get API errors that you’re unsure about it’s good to check this link: https://developer.paypal.com/docs/classic/api/errorcodes/

Do a find on that page for the error code in question and you’ll generally find more details than what the API itself returns.

For example, you’ll see that error 15005 means the following:

The transaction was declined by the issuing bank, not PayPal. The merchant should attempt another card.

This can happen if somebody’s card is simply invalid, or if they’ve reached a daily limit on their account, or any other number of reasons. The buyer would need to call their bank to ask why it was declined if they’re unsure.