Identity theft is the fastest growing crime in the U.S. Luckily, there are steps you can take to head off some of this fraudulent activity. Stay alert, check your credit report often, and thwart thieves early to minimize damage and avert disaster. Here are eight red flags to look out for to help you avoid identity theft.

1. YOUR BANK ACCOUNT HAS UNKNOWN CHARGES.

If you don’t recognize charges or withdrawals, someone may have stolen your account info. Even if you only notice a very small amount of difference, call your bank immediately and tell them you suspect your account has been compromised.

2. YOU KEEP MISSING MAIL OR EMAILS.

Someone may have changed the contact information on your accounts or filed a change of address with the postal service, which would keep you in the dark on your statements. Visit your accounts’ web pages often to stay up-to-date on charges. Keep your mailing address current and shred all of your mail.

3. YOUR CREDIT REPORT LISTS ACCOUNTS YOU DON’T RECOGNIZE.

You should be checking your credit often; you are entitled to three free reports, one from each bureau, per year. Certain banks offer credit score checks for free, even if you’re not a customer. If you notice any anomalies—including hard inquiries for lines of credit you did not request or changes of address you did not initiate—alert the three credit bureaus’ fraud departments and dispute the accounts.

4. YOU GET COLLECTION CALLS ABOUT ACCOUNTS YOU DON’T HAVE.

If you receive strange, confusing calls from debt collectors, it’s easy to dismiss them as scams and ignore them. But it could be that someone opened an account in your name and never paid the bill. For extra peace of mind, check your credit report to confirm.

5. YOU RECEIVE UNUSUAL MEDICAL BILLS.

Someone may steal your insurance information, birthday, and Social Security number and use it illegally to receive medical treatment. If you don’t remember receiving medical care, alert your insurance company and healthcare providers about the strange charges.

6. YOU GET AN UNEXPECTED WARNING FROM THE IRS.

Someone may be using your Social Security number on his or her employment documents. If this is the case, the IRS will find discrepancies in your tax forms. Be suspicious if you receive a tax form in the mail from an employer you never worked for. The IRS will alert you if multiple tax returns are filed in your name or if you had income you did not claim.

7. YOU RECEIVE A TRAFFIC OR PARKING TICKET YOU DID NOT DESERVE.

If you receive a speeding or parking ticket in the mail that is simply not yours, contact the police department to dispute it and alert them to possible identity fraud.

8. YOU GET UNEXPECTED SOCIAL MEDIA MESSAGES.

If you are receiving social media messages from friends or family that do not make sense, someone may have hacked into your account and used your identity to target your friends and family members. Try contacting the message sender over a different platform to determine what happened. Change your password for extra protection.

Even if you’re vigilant, you can still be the target of identity thieves. That’s why it’s important to stay in the know. Discover® can help by monitoring thousands of risky websites and will alert you if they find your social security number. And it’s free for cardmembers who sign up. Learn more at Discover.