Why did I get API error code 10009?

Multiple issues can produce this error. These are explained in the following paragraphs.

Authorization and Capture API errors

If the account is locked or inactive, retry the request later or close the order.

RefundTransaction API errors

First, to resolve this issue, check that there is sufficient money in your PayPal balance.

The following errors can also produce error code 10009:

The bank account attached to your PayPal account is not verified.
The partial refund amount isn't less than or equal to the original transaction amount.
The partial refund amount isn't less than or equal to the remaining amount.
The partial refund amount is invalid.
If a buyer opened a dispute for a transaction, only the full or remaining amount can be refunded.
The time limit to refund this transaction has been exceeded.
A full refund can’t be issued after a partial refund.
Check if your PayPal account is locked or inactive.
Check if your PayPal account has a limitation.
The partial refund isn't in the same currency as the original transaction.
This transaction has already been fully refunded.
This type of transaction can’t be refunded.
A partial refund of this transaction can’t be issued.
The account for the buyer is locked or inactive.

DoReferenceTransaction errors