We're here to help when the unexpected happens.
During NORMAL BUSINESS hours
To report a lost or stolen Diamond VISA or MasterCard, or for other card problems such as fraud on your card or declined transactions, contact Diamond Card Services during normal business hours (Eastern Standard Time) at 610-326-5490 or toll-free at 800-593-1000.
During NON-BUSINESS hours
VISA Debit Cards
To report a LOST or STOLEN VISA debit card:
Dial 888-241-2510 in the U.S. and follow the prompts (or 001-909-941-1398 Internationally).
For DECLINED VISA debit card transactions, or to REPORT FRAUD on your VISA debit card:Dial 800-593-1000, option 3 and follow the prompts.
NOTE: Your debit card activity is monitored 24 hours a day, 7 days a week for suspicious activity by our Fraud Alert Management Services Team.
If you received a phone call from our Fraud Specialists which was prompted by possible suspicious activity on your debit card, please follow the instructions given to either confirm the activity as valid, or report the activity as fraud. If you have any questions about this fraud monitoring service, or any calls you may have received, please call 800-593-1000 at any time.
Mastercard Credit Cards
To report a LOST or STOLEN MasterCard credit card:
Dial 800-449-7728 in the U.S. and follow the prompts (or 001-727-299-2449 Internationally).
For DECLINED MasterCard credit card transactions, or to REPORT FRAUD on your MasterCard:
Dial 888-918-7313 and follow the prompts (or 001-727-299-2449 Internationally).
For GENERAL INQUIRIES on your MasterCard:
Dial 866-820-3791 and follow the prompts.
Send us an email.
To send an email, visit our Contact Us page and choose General Questions/Other from the drop down menu.
PLEASE NOTE: Email will not be responded to until the next business day during normal business hours.
It is extremely important that you provide Diamond with your updated contact information, including cell number and email address so that we can reach you regarding suspicious debit card or credit card activity.
Download the CardNav app for extra security. Stop fraud before it occurs through card controls. Real-time notifications will enable you to turn off the card immediately. Also the spending control feature can help to better manage your spending habits.