These days, you can’t open your mailbox without discovering at least one envelope stuffed with the latest application for a hassle-free, pre-approved credit card. Some days, of course, such unsolicited spam is the only correspondence you get.

It’s enough to drive any consumer mad. Unless, that is, you dial up what’s known as the Credit Reporting Industry Opt-Out Number. The toll-free call (888-567-8688) has been set up so Americans can remove their names from the screening lists of the four largest credit-reporting companies in the nation: Experian, Novus, TransUnion, and Equifax. The effort stems from the federal Fair Credit Reporting Act, which creates rules and procedures to ensure that credit-reporting agencies respect people’s privacy, and which Congress passed in January 2002. Under the law, Joe and Jane Q. Public can " elect to have [their] name and address excluded from any list provided by a consumer-reporting agency " simply by notifying the " system maintained by the agency. " Hence, the industry’s opt-out number.

Word of the hotline has spread quickly, thanks, ironically, to the wonders of advertising. Fliers, mail coupons, and e-mail messages have all circulated the number. Consumers should beware, however, that opting out doesn't get their credit information out of the Big Four systems altogether. But some of the claims made by the opt-out-program circulars have also been overstated. For instance, one recent e-mail that’s been forwarded around like wildfire warns that the Big Four credit-reporting bureaus will be allowed to release people’s personal credit information to " anyone who requests it " as of July 2003. That borders on hyperbole. In fact, the Fair Credit Act entitles these Big Four companies to release people’s names, addresses, and phone numbers to third parties, but not to anyone. Only " legitimate businesses that have permissible purposes, " as the legislation states — including insurers, government agencies, employers, the courts, and businesses processing transactions " initiated by the consumer " — will have legal access to such material.

But even if you can’t halt access to your information entirely, you can prevent the Big Four companies from putting your name on its marketing lists, which credit-card and loan outfits then use to woo potential applicants. So take a few minutes, key in your vital statistics, and wipe your name off the rolls for good. It takes just five business days for you to be free of aggravating unsolicited spam — and for your mailbox to become, simply, free.