Reason code

American Express reason code S03 is a status notification indicating that Amex has received the merchant’s supporting documentation in response to a dispute. It doesn’t mean the case is resolved yet—only that the evidence is under review and the chargeback process is ongoing.

This code serves as a checkpoint in the dispute lifecycle, confirming the merchant’s timely response. While no action is required at this stage, merchants should stay alert for follow-up communications or resolution updates from Amex.

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No action required at this time—Amex has acknowledged your submitted documentation:

• Monitor the case for further updates or resolution notices
  
  
• Retain a copy of your submission and confirmation for reference

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Continue responding promptly and thoroughly to disputes to maintain your strong position:

• Use a system that tracks deadlines and confirms delivery of all submissions
  
  
• Prepare documentation templates in advance for faster, more effective responses

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