Consumers can now freeze their credit for free under a new federal law.

A credit freeze restricts access to your credit file, essentially halting anyone from opening any new credit in your name. The rules used to vary by state, but previously it could cost up to $10 to put a freeze in place. That fee often had to be paid again when someone wanted to unfreeze it for any legitimate uses.

But under a new law that takes effect Friday, consumers anywhere in the U.S. can do so quickly and for free.

Congress passed the law in response to last year’s massive Equifax hack, which exposed the private information of more than 145 million Americans. President Donald Trump signed it into law in May.

The law requires that credit freezes be free for consumers across the country. If the request is made over the phone or online, the freeze must be completed within a day. If the request is made by mail, within three days of receiving the request.

Lifting the freeze is also free and must be done within the hour if the request was made by phone or online; three days if by mail.

Consumers who want to freeze their credit should visit the websites of all three credit reporting agencies — Equifax, Experian and TransUnion — to make their request at each. The FTC also will have links to those pages on its identity theft information website: www.identitytheft.gov

Additionally, the law allows for a free credit freeze for children under age 16, something that was not previously allowed in all states. This helps prevent criminals from creating fraudulent accounts under a child’s identity, a problem that often goes undetected until they are adults and seek credit of their own.

A credit freeze, which is different from credit monitoring, is considered one of the most effective ways to protect criminals from opening credit in your name.