The chances are that you’ve been pitched to by a door-to-door salesman at some point, and possibly about switching your energy tariff.

And now that summer's here, we'll be seeing more and more of them.

However, it’s best not to fall for the charm and the patter, because a man at your doorstep with a clipboard is unlikely to get you the best deal. In fact, you could end up paying over £180* per year more than you might otherwise pay for the best tariff from the same provider.

The reason for this is simple. The salesmen don’t offer online tariffs, which are the cheapest type of tariff by a long chalk. This basically means that the estimated 41% of consumers who switch as a result of door-to-door sales** are losing out.

As appealing as a salesman’s pitch may be, don’t be suckered by claims such as ‘the cheapest capped  tariff’ or ‘the cheapest standard tariff’ – an online tariff is almost always the most competitively priced.

This isn’t to say that a door-to-door salesman won’t save you money. If you have never switched provider or tariff before, then there’s a good chance that they will. However, they probably won’t save you as much as you might save otherwise from being presented with a wider range of options.

If you’re not a fan of leaking money unnecessarily, then the best way to get a sweet deal is to compare tariffs available in your area with an accredited comparison site. Consumer Focus accredited sites such as Confused.com compare all the available tariffs on the market – including the online ones – to ensure that you can make a fully-informed choice.

And don’t worry if you don’t have regular access to the net... There are online tariffs that don’t necessarily have to be administered online – just set up that way.

For an indication of the best providers and tariffs, see our current best buy table.

These tables can be useful as a general guide, but it's worth bearing in mind that the information they provide is limited – and based on assumptions of energy consumption, and a national average price. If you want to find the best deals for your personal circumstances, accredited comparison sites are totally the way forward.

* The figures below show not only the difference in cost of the best tariff that can be offered on the doorstep versus the best online for each provider, but they also show the difference in price between providers themselves.

Calculations made assuming national average price and OFGEM medium consumption – 3,300kWh electricity, 20,500 kWh gas.  Assumes bills are paid by monthly Direct Debit. Prices correct as at 11/06/10.