Most people only freeze credit with the three major bureaus. But criminals can also open services in your name with smaller specialty bureaus that report to different industries.
Specialty bureaus to contact:
Innovis (the "fourth bureau"—less known but important): innovis.com/optout or call 1-800-540-2505. Request a credit freeze.
LexisNexis (used for insurance, utilities, telecom): optout.lexisnexis.com or 1-866-797-3579.
Clarity (used by lenders): clarityservices.com or 1-800-262-0299.
ChexSystems (used by banks for checking accounts): chexsystems.com/consumer or 1-888-696-4642. You can't freeze here, but you can place a fraud alert.
These bureaus specialize in different data. Someone might open a cell phone account using your SSN and address. If you've frozen these specialty bureaus, they can't.
Also contact your utility companies, phone companies, and internet providers directly. Ask them to add a password or PIN to your account. Require this PIN before making changes—adding services, upgrading, or transferring.
Most companies will do this at no cost. Some require you to visit in person. It's worth the trip because utilities are often opened first in fraudulent identity theft. A fraudster gets your SSN, opens a $2,000 electric account in your name, then disappears. You're stuck with the bill and damaged credit.
For people with bad credit, utility fraud is common because you're already vulnerable. Criminals assume you won't notice another bill.