A worrying number of people stick with their energy supplier because they think switching is a long and difficult process. Because of this, they end up overpaying when they could be saving money by moving to a cheaper provider. These days it's extremely easy to switch: you can even do it on the bus. Here we'll explain how to use the free Voltz app to choose a new gas and electricity supplier. See also: Best cheap smartphones

There are lots of online services that let you switch, but the Voltz app (available on the App Store and Google Play) is arguably easier to use on a smartphone and also keeps you up to date with the best deals so you can ensure you're always on the best tariff.

It uses your real usage, rather than estimating, which means you can be more confident that you'll actually save money. What you'll need, however, is a good idea of how much you pay for your gas and electricity each month or the figures (in kWh) for your annual usage. These are typically found on your paper bill, but you should also be able to call your current supplier to get the breakdown for the monthly costs, or the annual usage figures.

One of the features of Voltz is that it supports the new government initiative 'midata'. This means the app can access your actual energy usage - a feature that will be useful when more energy companies sign up to participate. Currently only First Utility has, so if you're with another provider you'll have to enter your usage manually.

How to switch energy suppliers in 5 minutes using your smartphone

Step 1. The app is available on Android and iOS (not yet on Windows Phone) so search for Voltz and install it - it's free.

Step 2. When you launch the app you have two choices: New user or Existing user. Obviously you need to tap New user to create an account. An email and password is all you need to enter for that.

Next, choose your energy options and tap Done.

How to switch energy suppliers in 5 minutes using your smartphone

Step 3. Select how you currently pay for your energy, then your current provider and exact tariff on the next screen. This is needed so the app can calculate whether you’ll pay less by switching to a different tariff or supplier.

Virtually everyone will need to tap the Add your usage info on the ‘monthly spend’ screen as the app will estimate your usage. Either tap in your annual consumption for gas and electricity, or the amount you pay for each fuel per month.

How to switch energy suppliers in 5 minutes using your smartphone

Step 4. When you tap next, the app will search to find better deals and the cheapest will appear at the top. Tap Full info to see more about the tariff including early exit fees for fixed deals (which most are).

You can tap the three horizontal bars to get to the menu and update your details, set alert preferences and see the best current deal.

How to switch energy suppliers in 5 minutes using your smartphone

Step 5. When you’ve chosen a tariff, hit the Start your switch button and – if it’s your first switch through the app – enter your personal details and then your bank details for payment. When we switched our gas and electricity meter reference numbers were filled out automatically, but you may need to look on your bill to find them.

Finally, tell the app if you have a smart meter and tap Next.  This completes the process and the switching process will get underway. You should hear from your new supplier – typically by post -and get a welcome pack  with all the information including the option to cancel during a ‘cooling off period’.

How to switch energy suppliers in 5 minutes using your smartphone

If you’ve chosen a tariff with no exit fees, you’re free to switch again as soon as you like using the app, which will alert you when it’s found a better deal as long as you’ve allowed it to give you notifications. (You can change this preference in the Alert settings in the menu, setting the frequency of alerts and the minimum amount of money to save before you get a notification.)

Handily, Voltz will also alert you before your tariff expires, so you’re always on the cheapest deal.