Sex chatting in text on mobile phones
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.
Area code 900 went into 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.
This type of scam was especially popular in the late '80s to early '90s in the United States before tougher regulations on the 900 number business forced many of these businesses to close.
A 1-900 telephone number, in the North American Numbering Plan, has the form 1-900-###-####, and is often called a 900 number or a 1-900 number ("one-nine-hundred").
Diplomatic services, such as the US Embassy in London or the UK Embassy in Washington, have also charged premium rates for calls from the general public.
In many European countries, for example France, Germany and the United Kingdom, it was common for organisations to operate customer service lines on premium-rate numbers using prefixes that fall outside the scope of the country's premium-rate number regulations.
For example, a "psychic hotline" type of 1-900 number may charge .99 for the first minute and 99 cents for each additional minute.
Numbers with the 900 area code were those which were expected to have a huge number of potential callers, and the 900 area code was screened at the local level to allow only a certain number of the callers in each area to access the nationwide long distance network for reaching the destination number.
Also, the early incarnation of 900 was not billed at premium-rate charges, but rather at regular long distance charges based on the time of day and day of week that the call was placed.
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.
The law killed the adult 900 number business, which moved over to 800 numbers, where billing had to be done by credit card.
Other early leaders in amassing huge volumes of revenue were the New Kids on the Block and Dionne Warwick's Psychic Friends Network.