 This is not the same as telephone slamming, where an existing vendor is replaced with a rival without the client's informed consent.In the UK all the UK mobile operators have a third party direct to bill scheme (chargetomobile 'payforit') controlled by the Payforit Scheme Rules which prevent unauthorised charging.In the USA an effort to prevent instances of cramming, some members of the third party billing industry have implemented screening and monitoring measures to identify and eliminate crammers.