Watch out for 070 codes. They look like mobile phone numbers, but can cost up to 50p a minute. 070 phone numbers are intended to act as a forwarding service – known as personal numbers, they divert calls to the owner's location.
However, because they are easy to mistake for mobile phone numbers, some criminals use them to try to con you into calling them and making money out of it. If you receive a missed call on your mobile from an 070 number, do not call it back – it is likely to be a scam. [Which 2011]