Another now-uncommon premium-rate scam involves television programming that induces young children to dial the number, banking on the notion that they will be unaware of the charges that will be incurred.
While the billing is different, calls are usually routed the same way they are for a toll-free telephone number, being anywhere despite the area code used.
These telephone numbers are usually allocated from a national telephone numbering plan in such a way that they are easily distinguished from other numbers.
Adult entertainment 900 numbers have been largely absent from AT&T and MCI since 1991.
In 1992, the Supreme Court allowed a law passed by Congress that created a block on all 900 numbers that provided adult content, except for those consumers who requested access to a specific number in writing.
Computer criminals have used premium-rate numbers to defraud unsuspecting Internet users.
One scheme involved inducing users to download a program known as a dialer that surreptitiously dialed a premium-rate number, accumulating charges on the user's phone bill without their knowledge.
Area Code 900 went in to service January 1, 1971, but the first known to have been used in the United States for the "Ask President Carter" program in March 1977, for incoming calls to a nationwide talk radio broadcast featuring the newly elected President Jimmy Carter, hosted by anchorman Walter Cronkite.
At that time, the intent for area code 900 was as a choke exchange—a code that blocked large numbers of simultaneous callers from jamming up the long distance network.
Adult chat lines (phone sex) and tech support are a very common use of premium-rate numbers.