The lock was circling, but I figured it would take 10 seconds. After all, there are roughly 200 million individual credit files. That could take a while.

But several more seconds passed, and I started counting. I got to 90 before I was booted back to the sign-in screen.

I gave it another try. And another. And another still.

That’s when we told Equifax. About 90 minutes later, a spokeswoman said the company had identified the issue and resolved it.

Except that it hadn’t. The locking mechanism still wouldn’t lock. A company spokeswoman said Equifax had not experienced widespread issues with the service, but, as with any new product, there had been isolated problems they were working to resolve. She also offered to put me on the phone with a technical support representative.

Why go to all of this trouble to cut off access to your credit file? Credit-card issuers, mobile phone companies and others generally won’t do business with you without first checking your credit report with at least one of the three major bureaus: Equifax, Experian and TransUnion.

If companies can’t get to your file, they won’t issue credit. That protects you when thieves get access to your information and then try to open new accounts in your name.

Image Equifax declined to promise that its push toward locks would not cause the loss of legal or regulatory protections.

Shutting companies out of your credit files has traditionally meant initiating something called a credit freeze. It often costs a few dollars and you have to use a PIN — which you may not remember or could lose — to temporarily lift the freeze when you do want to authorize access to your credit file. Getting a new PIN takes a fair bit of tedious work. (For a longer primer, see our consumer guide to the Equifax breach.) Freezes are also subject to a variety of state laws.