Target says that personal information - including phone numbers and email and mailing addresses - was stolen from as many as 70 million customers in its pre-Christmas data breach.
That was substantially more customers than Target had previously said were affected.
Target had announced in December that about 40 million credit and debit cards may have been affected by a data breach that happened between Nov. 27 and Dec. 15 - just as the holiday shopping season was getting into gear.
The retailer said Friday that the personal information stolen is not a new breach, but was discovered during its ongoing investigation.
Target Corp.'s stock fell in Friday premarket trading.