A fixed tariff means that the unit rates and standard charge won't change, but payments can change up if consumption increases or isn’t in line with the estimates provided at the time of your switch. However we sometimes hear of problems because your provider has made incorrect calculations about your usage pattern or assumed that you'll stay on its standard tariff when your fix ends.
If you don’t already, do try to provide your supplier with regular meter readings. This’ll help it to keep on top of your usage and then your direct debits may be decreased in the future.
Plus if you feel that your supplier has increased this direct debit payment unfairly, then you can challenge it.
For more on this please take a look at our story which covers this in more details.