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.
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.
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.
One variant, targeted at children too young to dial a number, enticed children to hold the phone up to the television set while the DTMF tones of the number were played.
Premium-rate telephone numbers are telephone numbers for telephone calls during which certain services are provided, and for which prices higher than normally are charged.
Unlike a normal call, part of the call charge is paid to the service provider, thus enabling businesses to be funded via the calls.
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.
Telephone companies typically offer blocking services to allow telephone customers to prevent access to these number ranges from their telephones.
In some jurisdictions, telephone companies are required by law to offer such blocking.
Adult chat lines (phone sex) and tech support are a very common use of premium-rate numbers.
Other services include directory enquiries, weather forecasts, competitions and voting (especially relating to television shows).