We received a debit card dispute from a customer on 11-26-2014. The customer provided a police report that he filed with the police on 11-23-2014. The customer let his grand daughter used his debit card to buy some parts for her car. During this time, someone stole the card information and conducted unauthorized transactions.

My question is under the MasterCard zero liability where it states that the customer must "promptly" notify us. What is "promptly"?

The customer knew about it on 23rd, but waited to till the third business day to notify us.

As I recall, MasterCard refrained from defining "promptly," and left it to the issuer to do. If you haven't already defined it for your customer in a disclosure update, I think the horse is out of the barn on this particular case. I've seen discussions in these forums suggesting that two business days could be prompt, but I still think you have to define it before you can enforce it.

I'm happy to defer to someone better versed in MasterCard's rule.

I agree with John that the issuer can define prompt and many are using the Reg E standard of two business days. If you attempt to enforce "prompt" without a more specific definition, a good attorney could probably argue against the Bank and win if the case every came to trial.

Next question, were there any additional unauthorized charges between 11/23/14 and 11/26/14? If there weren't remember you cannot go back to earlier transactions to enforce higher liability limits under Reg E.

Transactions occurring on business day 0-2 $50.00
Transactions occurring on business day 3-60 days after delivery of first statement $500.00
Transactions after day 60 of delivery of first statement: unlimited

We sent a disclosure to our customers about the Master Card liability changes, but did not define "promptly"... We will be adding a statement message defining promptly as two days.

Thank you for your help.

When you do that, make sure you indicate two days from some specific event. The only event that makes sense is the day the customer learns of the loss or theft of the card.