experiencing 10481 error in paypal

Question

Does anyone have an idea what "PaymentAction of Authorization is not allowed with Unilateral and Non-Credentialed authentication" means? I've been getting this error while trying to implement an authorization and capture transaction using paypal.

Answer 1

This happens when SUBJECT emailaddress belongs to registered Paypal account, but authorization is not permitted by the SUBJECT account.

Background: Let's have account A with known API credentials and account B that belongs to third-party merchant on whose behalf account A is calling the API operation. In order to complete authorization you call DoExpressCheckoutPayment method with A's API credentials and B's email as SUBJECT. This operation will fail unless you allow account A to authorize payments to account B.

How to enable authorization and capture permission: Login to account B, choose tab "My account", click subtab "Profile". There is a column named "Account Information" in which choose "API Access link". Then click on "Add or edit API permissions". Here you can Add New Third Party. Type A account email as "Third Party Permission Username" and check "Authorize and capture your PayPal transactions." Finally save it by clicking "Add". Make sure you have also checked operations necessary prior to authorization like "Use Express Checkout to process payments". Now A can authorize payments to B :)