Is there a specific time frame that a customer has to file true merchant dispute (in this case a defective product)? We understand it is not a Reg E Dispute and we still need to assist the customer per MC rules. This has been going on a few months between the merchant and our customer and the customer just contacted us about it and wants to see if we can help. How long is too long or is there even a time limit? The original charge was October of 2020.

Chargeback timeframes are governed by Mastercard. Timeframes are generally 120 days from the transaction date. However, for chargeback reasons such as services not rendered or merchandise not received, the 120 day clock starts on the promised delivery date of the merchandise or completion date of the services up to 540 days from the transaction date.

For defective merchandise, the Chargeback Guide states the following depending on your circumstance:

120 calendar days from when the services ceased with a maximum of 540 calendar days from the transaction settlement date for issues of interruption of ongoing services
Between 15 and 120 calendar days from the transaction settlement date
Between 15 and 120 calendar days from the delivery/cancellation date of the goods or services.

Thank you BrianC. You are always so helpful. :-)