The Federal Trade Commission (FTC) on Monday released an alert to provide affected users with recommended precautions against identity theft after the recent breach of the Marriott International Starwood guest reservation database.

According to Marriott, the hackers accessed people’s names, addresses, phone numbers, email addresses, passport numbers, dates of birth, gender, Starwood loyalty program account information, and reservation information. For some, they also stole payment card numbers and expiration dates.

Marriott says the payment card numbers were encrypted, but it does not yet know if the hackers also stole the information needed to decrypt them.

The hotel chain says the breach began in 2014 and anyone who made a reservation at a Starwood property on or before September 10, 2018 could be affected. Starwood brands include W Hotels, St. Regis, Sheraton Hotels & Resorts, Westin Hotels & Resorts, Le Méridien Hotels & Resorts, and other hotel and timeshare properties.

Marriott says customers can sign up for a year of free services that will monitor websites that criminals use to share people’s personal information.

Other precautions according to FTC include:

  • Check your credit reports from Equifax, Experian, and TransUnion — for free — by visiting annualcreditreport.com. Accounts or activity that you don’t recognize could signal identity theft. Visit IdentityTheft.gov to find out what to do.
  • Review your payment card statements carefully. Look for credit or debit card charges you don’t recognize. If you find fraudulent charges, contact your credit card company or bank right away, report the fraud, and request a new payment card number.
  • Place a fraud alert on your credit files. A fraud alert warns creditors that you may be an identity theft victim and that they should verify that anyone seeking credit in your name really is you. A fraud alert is free and lasts a year.
  • Consider placing a free credit freeze on your credit reports. A credit freeze makes it harder for someone to open a new account in your name. Keep in mind that it won’t stop a thief from making charges to your existing accounts.