Credit freeze vs. fraud alert vs. credit lock: which one do you need?

What all three are protecting

When someone applies for a loan or a card, the lender checks the applicant's credit file at one or more of the three national credit bureaus: Equifax, Experian and TransUnion. A criminal with your name, date of birth and Social Security number can apply as you, and the debt lands on your file.

A freeze, a fraud alert and a lock all make that harder. They differ in how firmly they block it, how long they last and what they cost.

Credit freeze: the strong, free default

A freeze, also called a security freeze, blocks new lenders from seeing your credit file. Since a lender will not approve an application it cannot check, new accounts cannot be opened in your name while the freeze is on.

Placing and lifting a freeze is free by federal law. You have to do it separately at each of the three bureaus, online or by phone, and each gives you a way to lift it later. It stays in place until you remove it.

• It does not affect your credit score.
• It does not affect accounts you already have. Your cards keep working.
• Your existing lenders and you yourself can still see your file.
• When you apply for credit, you lift the freeze, for a set period or for good, then put it back. Online, a lift usually takes effect within minutes.

Fraud alert: a note asking lenders to check

A fraud alert leaves your file visible but attaches a notice telling lenders to take extra steps to confirm it is really you, typically by calling you, before opening an account.

It is free. You only need to ask one bureau, which must pass it to the other two. A standard alert lasts a year and can be renewed. People who have been victims of identity theft can request an extended alert that lasts seven years.

An alert is weaker than a freeze, because it relies on the lender to follow the instruction. Its advantage is convenience: you can still apply for credit without lifting anything.

Credit lock: the bureaus' own product

A lock does much the same job as a freeze, switched on and off through a bureau's app. It is a commercial product, not a legal right. Depending on the bureau, it may be free or bundled into a paid monitoring subscription, and the terms are set by the company and can change.

For most people a freeze gives the same protection, at no cost, with rights set by law. A lock makes sense mainly if you already pay for a service that includes it and prefer the app.

What none of them do

That is why a freeze is paired with the basics: strong unique passwords, two-factor authentication, and looking at your transactions regularly.

• They do not stop fraud on accounts you already have. A stolen card number still works until you report it.
• They do not stop someone taking over an existing account by resetting its password.
• They do not stop tax refund fraud or medical identity theft.
• They do not block every check. Some landlords, employers and insurers use other reports.

Which one to use

• Nothing has happened and you are not about to apply for credit: freeze at all three bureaus. It is free and you lose nothing.
• Your details were in a breach, or you think they may have been stolen: freeze, and add a fraud alert if you want both.
• You are in the middle of a mortgage or loan application: a fraud alert, or a freeze you lift for the lender.
• You are a confirmed victim of identity theft: freeze, extended fraud alert, and file a report at IdentityTheft.gov.

Do not forget the rest of the household

A parent or guardian can freeze a child's credit file, which is worth doing because a child's clean record can be misused for years before anyone looks. You can also help an elderly relative place a freeze, since older adults are frequent targets.

And keep an eye on your own file. You are entitled to free copies of your credit reports from the three bureaus through AnnualCreditReport.com. A freeze does not stop you reading your own report.