Message type: E = Error
Message class:  SLS_PAYSP - Payment Service Provider Integration 
Message number: 015
Message text: Payment cards not permitted; payment by payment service provider
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The SAP error message SLS_PAYSP015 indicates that payment cards are not permitted for a specific transaction, and that the payment must be processed through a payment service provider (PSP). This error typically arises in scenarios where the system is configured to restrict direct payment card processing and instead requires the use of a PSP for handling payment transactions.
Cause: Configuration Settings: The system may be configured to only allow certain payment methods, and payment cards may not be included in the allowed methods for the transaction type or customer. Payment Method Restrictions: The payment method used in the transaction may not be set up to allow direct payment card processing. Transaction Type: The specific transaction type may not support payment card payments directly and requires a PSP. Customer Master Data: The customer’s master data may have restrictions that prevent the use of payment cards.
Solution: Check Configuration: Review the configuration settings in the SAP system related to
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