EDF Energy is to rise prices by 3.9% on 3 January 2014, hitting 2.4 million customers with an average increase of £158, taking the average dual fuel bill to £1,300.
E.On is also expected to usher in a 6.6% increase, meaning Britain's households finally know what all of the Big Six have in store for them this winter.
Of those who had already announced rises, Npower customers were worst hit, with their bills rising by 10.4%; while British Gas customers will have to stump up 9.2% more. Scottish Power customers will pay 8.6% more and SSE customers will see their bills rise by 8.2%.
EDF congratulated itself on putting up customer bills by just half the rate of its rivals when it announced its price increase this morning, but the rise still dwarfs inflation at 2.2%.
However, MoneySupermarket.com said EDF customers have seen bills rise by a total of £171 since October 2012.
Meanwhile, the Debt Advisory Centre has warned that 10% of gas and 9% of electricity customers with pre-payment meters are already cut off at least once a week because they run out of credit – and that's before this winter's price rises come into effect and the winter cold snap starts.
Ian Williams from the Debt Advisory Centre said: "When energy gets even more expensive, and temperatures really start to drop, pre-payment meter customers could find that they use up their credit more quickly – and the worry is that they won't be able to afford to top up straight away.
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"For customers who are elderly or who have young families, this could become a very serious problem."
What can you do to keep control of your energy bills?
Tom Lyon, energy expert at uSwitch.com, says there are two golden rules: "Make sure you are paying the lowest price possible for your energy by moving to a competitive deal and use less energy by making your home more energy efficient. These are everyone's best protection from the high cost of household energy today."
For customers prepared to switch, one of the cheapest fixed tariffs currently available is First Utility's iSave Fixed v9 April 2015, which would see the average dual-fuel customer paying £1,170.48 a year. This is followed by Sainsbury's Energy Online October 2014, which costs £1,172.15 a year.
Of the Big Six, the cheapest fix is currently offered by Npower, with its Online Price Fix November 2014, costing on average £1,182.03 a year.