Until recently, it's not been easy being an energy supplier. Many utility companies have been criticised by the industry watchdog, Energywatch, for causing debt by the late issuing of bills and for not passing on savings enjoyed by households that switch suppliers - as much as £100 per year. Andy Jackson takes a look at the report and offers tips to make sure you get the best deal for your gas and electricity.

Consumers are missing out on savings offered by electricity suppliers according to a report from the National Audit Office (NAO), a government watchdog.

Almost two-thirds of homes in England and Wales have stayed loyal to the power suppliers used before the sector was deregulated. However, if a household switched to another company, it could save up to 22% of their annual bill - around £50 - £100 according to the Consumers' Association 'Which?' magazine.

So have so many households stayed put? 'Customer inertia' was one explanation offered by the watchdog, along with horror stories of pushy salespeople who employ devious tactics to get households to switch.

But the report stated that customers that had switched their electricity supplier at least once since 1998 had cut their bills by as much as 17%.

The NAO twisted the knife into the backs of electricity suppliers further by questioning why customers loyal to their existing suppliers hadn't received some of the savings enjoyed by those that had switched. It recommended that the electricity regulator, Ofgem, should investigate.

After the report was launched on Friday, the rate of households switching suppliers trebled, so if you're considering a change, here are a few pointers:

• There are more than 20 gas and electricity suppliers in the UK and comparing the prices between them is now very easy.

Energywatch, for example, publishes comparison tables six times a year on its website, www.energywatch.org.uk. The tables show in pounds and pence how much you can save.

You can also get an idea about the customer service records of suppliers as the site contains details of actual complaints, not just customer satisfaction indicators.

• You can also give to Christian Aid by switching supplier. Find out how this is achieved and compare companies that service your area by clicking here.

• Many suppliers offer 'dual-fuel' deals where they will supply you with gas and electricity. The plus side of such deals is that you get a combined bill from one supplier. However, they can be more expensive than getting your gas and power separately.

• If you pay by direct debit, you can save up to 10% on your bill as suppliers don't have to chase late payers and they pass on that saving to consumers.

• For money saving tips in the home, as well as grants available to homeowners: contact the Energy Efficiency Hotline on 0845 727 7200 or its website.

• If you believe something has gone wrong with a change in supplier, recently introduced regulations mean that you have seven days from the date you receive the written confirmation to cancel the contract.

If you cancel your contract, is best to put this in writing and keep a copy of the correspondence.

If a company contacts you by telephone, make sure you keep a note of the conversation and the person's name.

Owing to the number of complaints and publicity independent companies have received, there are better than average procedures in place for dealing with complaints.

• If you have problems, call the Energywatch helpline on 08459 060708 or e-mail enquiry@energywatch.org.uk.