A credit freeze prevents credit bureaus from sharing your credit report with any person or lender without your permission.

“If you’ve been the victim of a data breach or identity theft, a credit freeze is a good way to mitigate the risk of further damage to your finances and identity,” says Greg Mahnken, credit industry analyst with Credit Card Insider. “If an identity thief or unauthorized person tries to apply for credit in your name, they will not be able to access your credit reports and the application will be denied.”

A credit freeze doesn’t damage your credit and you can lift it when you need a credit check, like when you’re applying for a loan or opening a credit card. However, you do need to contact each of the three credit bureaus (Equifax, Experian, and TransUnion) to place the freeze, and you must contact them again when you want to lift it, even temporarily.

Here are the steps you need to take to freeze your credit:

How to freeze your credit

1. Gather your information

You'll need to request the freeze from each of the major credit bureaus. It's important to note that they will not notify each other, so you'll need to freeze your credit from all three bureaus individually, says Mahnken.

For each of the bureaus, you'll need to provide personal information including your full legal name, Social Security number, date of birth, and home address.

2. Reach out all three credit bureaus

This can be accomplished online, by phone, or by mail. These three credit bureaus are Equifax, Experian, and Transunion.

How to do an Equifax credit freeze: You can easily freeze your credit with Equifax on its website, or via an automated phone line: 1-800-685-1111 (1-800-349-9960 for New York residents). If you'd rather talk to a human, its customer care number is 1-888-298-0045.

How to do an Experian credit freeze: To freeze your credit at Experian, you can visit its online Freeze Center. You can also call 1-888-EXPERIAN (1-888-397-3742).

How to do a TransUnion credit freeze: TransUnion allows you to place a credit freeze online. You can also add a freeze via the automated phone system (or opt to speak to a live agent) by calling 1-888-909-8872.

There is no cost for credit freezes by law as of September 2018.

"Freezing your credit is an effective, cost-free way to make it harder for thieves to open up credit cards or other financial accounts in your name," says Credit Karma's VP and financial advocate, Dana Marineau. "But keep in mind that it can be a hassle to remove a freeze from all three bureaus every time you need a credit check."

According to the Federal Trade Commission, after receiving your freeze request, each credit bureau will provide you with a unique PIN (personal identification number) or password. Keep the PIN or password private and in a safe place. It will be needed when and if you choose to lift the freeze.

3. Understand how to unfreeze it

A credit freeze can be lifted at any time online or by phone, and will remain in place until you ask the credit bureau to temporarily lift or remove it.

If you request a lift of the freeze, the credit bureau must lift it within one hour, according to the Federal Trade Commission. If you make your request by mail, the credit bureau must lift the freeze within three business days after it gets your request. There is no charge to lift the credit freeze.