This means you are able to shop around for a better price.

 How Does It Work?

The first thing to understand is that you don't need to understand how it works.  Basically you have to fill out a few forms to tell the new provider that you want to use them and they then contact your old provider and sort it out.  Your old provider sends you a final bill at the date you switch and the new provider sends you bills in the future.

There's no rewiring, laying pipes or any of that sort of thing involved.  While the pipes/cables may belong to your local company, that all gets sorted out by your new provider and is built into their costs. 

The supply of the gas/electricity just works the same way.  The easiest way to think about it is that when you use some electricity you are taking some from a big national pool of electricity.  Your new provider will put that amount back into the pool for you and you then pay them.

 How Much Could I Save?

This is hard to answer but you may be talking say £100 a year, depending really on how big your bills are and who your current supplier is. 

If you've never shopped around before then chances are you're likely to be able to get a better deal.

 What Now?

You can get an online savings estimate by getting instant quotes from most of the gas and electricity providers and seeing which is best for you.

You'll probably need an old electricity and gas bill to hand so you can work out how much you normally use and what your currently paying, but other than that the rest is just fully automated.