The Federal Trade Commission recommends the following four steps if you detect suspicious activity:

Step 1 – Contact the fraud department of one of the three major credit bureaus:

Equifax: 1-800-525-6285; www.equifax.com; P.O. Box 740241, Atlanta, GA 30374-0241
Experian: 1-888-EXPERIAN (397-3742); www.experian.com; P.O. Box 9532, Allen, Texas 75013
TransUnion: 1-800-680-7289; www.transunion.com; Fraud Victim Assistance Division, P.O. Box 6790, Fullerton, CA 92834-6790
Step 2 – Close any accounts that have been tampered with or opened fraudulently.

Step 3 – File a police report with your local police or the police in the community where the identity theft took place.

Step 4 – File a complaint with the Federal Trade Commission by using the FTC's Identity Theft Hotline:

By telephone: 1-877-438-4338
Online at www.consumer.gov/idtheft
By mail at Identity Theft Clearinghouse, Federal Trade Commission, 600 Pennsylvania Avenue NW, Washington DC 20580.