[spear]

You pay a one-time fee to each of the three credit bureaus. The fee varies by state (around $5-$10, may be less for seniors, usually free for identity theft victims). You can do this online.

If you need to unfreeze (eg. applying for a new credit card or a loan), you need to pay another fee per credit bureau, so you should find out which bureau will be used. You can unfreeze permanently, unfreeze for a short time period, or get an authorization code that you can give to whoever needs to check your credit report.

[jamra]

From one of the readings, contacting one bureau should be enough. They are obligated to contact the other two.

[stevewepay]

No, this is in the case of fraud, and then unlock it after 3 months. If you want it frozen until you rescind it, it costs $10 per bureau, but there may be an exception for fraud.