NATIONWIDE -- T-Mobile said on its website Friday that the personal information of about 2.3 million of its customers could have been compromised in a breach.

The company said it found and shut down an "unauthorized access" to the information Monday and reported it to authorities. 

It didn't say when the "unauthorized capture" first happened.

T-Mobile said no social security numbers or financial data, including credit-card information, was compromised. The exposed information included names, billing ZIP codes, phone numbers, email addresses, account numbers and account types.

The breach affected about 3 percent of T-Mobile's 77 million customers, it said. Affected customers were being notified.

"We take the security of your information very seriously and have a number of safeguards in place to protect your personal information from unauthorized access. We truly regret that this incident occurred and are so sorry for any inconvenience this has caused you," the company said on its website.

T-Mobile, T-Mobile for Business and Metro PCS customers with questions or concerns were urged to call Customer Care at 611.