We moved house in December 2012, my husband swopped from British Gas to n-power because they supplied the old owner. We use very little gas as its a new well insulated home and I have been nagging my husband to see what are bills are, he pays by direct debit and hadn't got a clue.
Well we got a paper bill on Friday and I was horrified to find out that we have been paying way over the odds to the tune of £700, they had put him on a standard tariff which is nearly 6p kw hr more for electricity,
We also have a smallholding so I rechecked the rates there as well and could also make savings there even though I had swopped in October.
So my advice would be check your rates on a regular basis and if you have family with no access to a computer get them to check theirs, if they are on standard rate they are paying far too much.