Use the complete notice and current processor guidance to interpret the Mastercard reason code.
Check the case
- Record the code and detailed description.
- Identify the disputed transaction.
- Check the stage and response deadline.
- Match records to the specific complaint.
One code can cover more than one type of issue. Read the case details before choosing evidence or a response structure.
Prepare the source record
Use the evidence checklist and submission workflow. For writing, see the response guide.