You may be a victim of identity theft and not even realize it. Have you received a letter from a bank you do not recognize confirming that your new line of credit has been approved? Or maybe a phone call from a credit card company informing you that your new credit card has been issued? Or a letter from the U.S. Post Office confirming an address change that you did not initiate? Each of these may seem trivial at the time, but they are just a few of the telltale signs of identity theft, which should be addressed immediately.

Identity theft happens when your personal information is stolen. Perhaps the thief steals your bank card or credit card, or the thief obtains your social security number and date of birth to open credit card accounts, credit lines or file for an income tax refund. Even the most prudent person can fall victim to identity theft. Sometimes we will never know how or where the thief obtained the victim’s information. If you are a victim of identity theft you should take these three actions.

1. File a police report with your local police department. This is a critical step, as it will allow you to place a seven year security freeze on your credit report. This will also serve to protect you in the future, because it establishes a record of the identity theft.

2. Contact credit reporting agencies and financial institutions. This is also an important step, as this will alert the credit agencies and financial institutions that someone has stolen your identity. This should prevent the thief from opening additional credit lines and accounts in your name. The Massachusetts Attorney General’s Office has an excellent guide on identity theft. The guide includes detailed information on (a) how to put a security freeze on your credit report; (b) how to put a fraud alert on your credit file, (c) what to do if checks have been written in your name, and (d) when to contact other entities, such as the Social Security Administration and the U.S. Post Office. The guide also has a list of useful phone numbers and contact information.

3. Change passwords. Change all of your passwords, even for accounts that have not been compromised. Do not use the same password for all accounts, and do your best to change and update passwords regularly.

It is important to take identity theft seriously, and to know that anyone can fall victim. Act quickly to protect your credit and your good name.