NEW YORK — Hackers have stolen personal information belonging to about 15 million T-Mobile wireless customers and potential customers in the United States, including Social Security numbers, home addresses, birth dates, and other personal information.
The hackers got the information from the credit reporting agency Experian, which T-Mobile uses to check the credit of consumers applying for phone plans and financing for their devices. Experian said that T-Mobile customers who applied between Sept. 1, 2013, and Sept. 16, 2015, may have had their information stolen.
Experian said it immediately notified law enforcement authorities after discovering the hack and that ‘‘there is no evidence to date that the data has been used inappropriately.’’
The companies said that payment card and banking information was not affected.
T-Mobile customers can sign up for two free years of credit monitoring at protectmyID.com/securityincident , a service owned by Experian.
The company said that affected customers should ‘‘remain vigilant’’ against identity theft and watch for phishing scams — e-mail that asks for sensitive information such as bank account and Social Security numbers.
Experian said in a statement on its website that it does not know who was behind the hack and that it is taking the ‘‘necessary steps’’ to prevent further breaches.
The hack happened on Experian’s server and is still being investigated, said Annie Garrigan, a T-Mobile spokeswoman.
There have been a string of high-profile hacks of businesses and other organizations in recent years, affecting millions of people, including the adultery website Ashley Madison, Sony Pictures, the insurer Anthem, retailers such as Home Depot and Target, eBay, and the US Office of Personnel Management.
Nearly 800 data breaches were reported last year by US organizations, according to the Identity Theft Resource Center.
‘‘I am incredibly angry about this data breach, and we will institute a thorough review of our relationship with Experian,’’ the chief executive of T-Mobile US, John Legere, said in a statement.
T-Mobile is now the number three wireless carrier in the United States, having surpassed Sprint this year.
The company refers to itself as an ‘‘Un-carrier’’ because it changed some of the wireless industry’s practices, such as replacing the two-year service contract with monthly installment plans.
Verizon and AT&T are the largest US wireless carriers.