Q: What is a credit monitoring service? I’ve been offered a free credit monitoring service after being a victim of a data breach. Should I sign up? Are there other services that can protect me from ID theft?

A: If you’ve been the victim of a data breach — and there’s a good chance you have — you’ve probably been offered free monitoring of your credit reports. Credit-monitoring services scan your files from the three credit-reporting companies — Equifax, Experian and TransUnion — and notify you of activity that could signal you’re the victim of fraud, such as a new account opened in your name. If you act quickly, you may be able to close the account before the fraudster has a chance to use it.

Free options: It’s not unusual for businesses that have suffered a data breach to provide free credit monitoring to those whose personal information was exposed. If you’re offered a free service, it’s usually a good idea to accept it.

If you don’t have access to credit monitoring as a breach victim, there are other avenues to get it without charge. Chase Credit Journey (www.chase.com/creditjourney), for example, will monitor your Experian credit report free, even if you don’t have financial accounts with Chase. Similarly, Capital One’s CreditWise (www.capitalone.com/creditwise), which provides free monitoring of your TransUnion and Experian reports, is available regardless of whether you are a Capital One banking customer. Another option is personal finance company Credit Karma (www.creditkarma.com), which provides monitoring of your TransUnion and Equifax reports; the service is free once you set up an account.

Ideally, you’ll get alerts of changes on your reports from all three credit-reporting companies. If you don’t have free access to a single service that monitors all your reports, you may want to sign up for a couple of different ones to be fully covered.

Paid services: For a monthly fee, the credit-reporting companies offer services that provide three-bureau credit monitoring and additional protection. For example, for $24.99 a month, Experian’s IdentityWorks provides insurance of up to $1 million to cover legal fees, lost wages and other costs incurred if you’re the victim of identity theft. TransUnion Credit Monitoring, which is $29.95 a month, notifies you when your personal information is detected on the “dark web,” where criminals buy and sell personal data, and gives you daily access to your credit score. For $19.95 a month, Equifax’s Complete Premier service provides identity theft recovery assistance from specialists and ID theft insurance of up to $1 million.

Credit expert Gerri Detweiler says a paid service may be worthwhile if you’ve been the victim of identity theft; otherwise, free credit monitoring should suffice.

Keep in mind that the federal government’s IdentityTheft.gov website provides free resources for victims. You can also contact the Identity Theft Resource Center (www.idtheftcenter.org; 888-400-5530) for help in the aftermath of identity theft.

Consider a credit freeze: While credit-monitoring services detect fraud after the fact, a freeze can prevent criminals from opening accounts in your name. When a freeze is in place, creditors can’t review your report in response to an application for a new loan or credit card. Contact each of the three credit-reporting companies to implement a freeze.

Even if you’ve frozen your credit, you should still check your credit reports regularly because a freeze may not stop all suspicious activity. You can view your reports from the three credit-reporting companies weekly for free at www.annualcreditreport.com.