Ask Which? – Will I be overcharged when energy prices go up?

…even though I used most of the energy when it was at the lower price.

Our energy expert James Tallack responds:

That’s a good question, and there are a lot of people in your situation. There are a couple of things you can do to make sure that you’re not overcharged for the energy that you have already used.

Read your meter on the day

If you don’t switch just after a price rise then don’t rely on your supplier to make sure you are only charged the increased prices for the units you use after the price rise takes effect.

Unless you have a smart meter, or your supplier happens to read your meter on the day your prices change, the supplier will have to estimate how many units you used up until the day of the increase.

Estimates can be notoriously inaccurate, so you could find yourself paying for units at the higher rates when they were actually used at the lower rate. The best way to avoid this happening is to contact your supplier by phone or online to provide meter readings the day your prices change.

Query expensive ‘catch-up’ bills

If you’ve been receiving estimated bills from your supplier then you might find that when your meter is finally read that the estimates were too low and there’s been a shortfall between what you’ve been paying and what you owe – known as a “catch-up bill”.

This can be even more problematic if your supplier has changed the prices on your tariff during the period you were receiving estimated bills.

If this has happened to you then make sure you aren’t automatically charged for all the excess units at the new price by ensuring your supplier spreads the excess units across the billing period concerned. If you’re not happy with the explanation you receive, complain.

To reduce the chances of receiving a catch-up bill, provide regular meter readings to your supplier and don’t rely on them reading your meter – by law they only have to do this once every two years.

Don’t pay increased prices or exit fees

And as an added bonus, here’s my top tip on price rises: if your supplier changes its prices, you don’t actually have to pay exit fees if you want to switch.

The rules energy suppliers have to comply with say that if they increase any of the charges set out in a customer’s contact then the customer has a right to get out of that contract. These include the cost of energy, but also cover other types of charges, such as late payment charges or changes to discounts.

As long as you tell your supplier you want to leave by the date the increased prices take effect, and your new supplier contacts your current supplier within 15 working days to tell them you’re switching, you will not have to pay the higher charges.

It’s particularly important to bear this in mind if you’re on a tariff where you have to pay exit fees if you break your contract early – these fees cannot be charged in the event of a price increase. If your supplier tries to charge you an exit fee or says you will have to pay the higher rates until your switch goes through then complain and refer them to Ofgem’s Standard Licence Conditions 23 and 24.