Approximately 40 million credit and debit card accounts used by Target customers may have been impacted by a major data breach, the retailer said Thursday. Customer names along with credit and debit card numbers may have been accessed, as well as the expiration date and three-digit security code on the back of each card, the store said.

Shoppers who made purchases at their stores between November 27 and December 15 should check their debit and credit card accounts and report suspected unauthorized activity to their financial institution. Target will also receive calls from customers who may have been victimized: 1-866-852-8680.

Target said in a statement that it was “aware of unauthorized access to payment card data that may have impacted certain guests making credit and debit card purchases” during the height of the Thanksgiving and Christmas holiday shopping period.

[WSJ, WVEC]