My boss and I have a differing opinion in regards to unauthorized transactions zero liability with mastercard and reg e disputes. In our disclosures it states that the customer needs to notify us in writing when there is a transaction on their account that they want to dispute. My boss believes that with any type of dispute/unauthorized transaction if we do not receive the request in writing we should not give provisional credit. I believe we should be giving provisional credit after 10 days regardless. Can someone clarify this for me??

I must agree with management in this situation, provisional credit is not required.

Refer to Reg E 1005.11(c)(i)(A-B)

(i) Provisionally credits the consumer's account in the amount of the alleged error (including interest where applicable) within 10 business days of receiving the error notice. If the financial institution has a reasonable basis for believing that an unauthorized electronic fund transfer has occurred and the institution has satisfied the requirements of § 1005.6(a), the institution may withhold a maximum of $50 from the amount credited. An institution need not provisionally credit the consumer's account if:

(A) The institution requires but does not receive written confirmation within 10 business days of an oral notice of error; or

(B) The alleged error involves an account that is subject to Regulation T of the Board of Governors of the Federal Reserve System (Securities Credit by Brokers and Dealers, 12 CFR part 220);

If you don't receive written confirmation, Reg E still requires that you complete your investigation in 90 days on a debit card claim (45 on an ATM withdrawal.)
MasterCard Zero Liability coverage is silent on provisional credit requirements. The only MasterCard requirement is that you credit the cardholder once you file a chargeback.

Combining Reg E and MasterCard rules and complying with both can be a challenge. I encourage you to check out my upcoming webinar Reg E vs. MasterCard: Debit Card Dispute Resolution

Thank you for your help.