There is an electricity prepayment meter scam 'doing the rounds' at the moment with over 230,000 incidents and 127,000 customers affected. Please take care to avoid getting caught out by these criminals.
The fraud operates by a criminal having a master key which they use to put 'credit' on your meter and negotiates a fee for doing so. However, energy use continues and debt for that energy accrues, usually unknown to the customer, until the next legal vend.
The industry is working to try and raise awareness by its customers, and all new meters manufactured since April 2011 will no longer respond to a master key. A security review is also being carried out by KPMG.
You can watch a video about the fraud here.
You can download a wide range of materials from the recent national prepayment meter fraud conference in Birmingham (held on 16 May 2011) here.