Error: 91517/91577 Payment instrument is not accepted by this merchant account/merchant account does not support payment instrument. What's going on?

Problem Statement

This article helps you understand 'error: 91517/91577 payment instrument is not accepted by this merchant account/merchant account does not support payment instrument. what''s going on?'.

Solution

91517 and 91577 are validation errors. These errors indicate that a particular card type (American Express for example) or a token (read about tokens here) associated with a particular card type isn't accepted by your merchant account. To resolve, you would need to reach out to your merchant account provider and enable the card type in question.