Mobile phone users are now able to keep their existing number when moving to another operator but will have to cover the cost of transferring, which could be as much as #25.
The scheme is the latest dictate from UK telecomms watchdog, Oftel to ensure competition. All of the UK's four mobile operators - Orange, Vodafone, One 2 One, and Cellnet - are affected.
David Edmonds, Oftel director general, said: "This will encourage much more intense competition in the mobile market as the four companies fight to win and retain customers."
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