Mint Mobile notified a “small number” of customers last weekend that their personal information was compromised between June 8 and June 10, when a threat actor ported the phone numbers of those customers to another carrier without authorization.

According to the breach notification sent to those customers, “While we immediately took steps to reverse the process and restore your service, an unauthorized individual potentially gained access to some of your information, which may have included your name, address, telephone number, email address, password, bill amount, international call detail information, telephone number, account number, and subscription features.”

Mint Mobile is strongly encouraging those customers to change the passwords on their accounts, monitor their accounts and “protect other accounts that use your phone number for validation purposes and to reset account passwords.”