Processing Errors
M38 Reversal
Details
American Express reason code M38 is used when Amex reverses a previously processed charge for any reason not covered by a more specific code. This could be due to errors in processing, failure to respond to an inquiry, or a determination made by Amex after reviewing the dispute case.
Unlike cardholder-initiated disputes, this type of chargeback is generally triggered by Amex’s internal processes or findings. It may serve as a final action following a failed response, insufficient documentation, or unresolved case details.
Timing to raise the dispute (Issuer/Cardholder)
Timing to respond to the dispute (Acquirer/Merchant)
How to respond?
If you believe the reversal was issued in error, review the case and respond with clear, complete documentation:
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Provide all original supporting evidence and note any inconsistencies in Amex’s decision
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If allowed, appeal through your acquirer or dispute management platform
How to prevent?
Prevent M38 chargebacks by ensuring every dispute is handled thoroughly and on time:
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Double-check that responses meet Amex’s documentation standards and are submitted before deadlines
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Keep detailed records of all customer interactions, authorizations, and fulfillment activity