The best time to switch energy suppliers will depend on your individual circumstances. If you haven’t switched for a few years, you should compare energy prices to make sure you’re on the best deal available to you.
For those on a fixed term contract, the best time to switch will be when your renewal window opens and you have no exit fees to pay. If you allow your contract to expire, you’re likely to be placed on your supplier’s standard variable tariff. This tends to be one of the most expensive tariffs your supplier offers.