The company's managing director, Graham Bartlett, claimed that the decision to increase costs was not an easy one to make.
He explained: "We've tried to keep these increases as low as possible while protecting as many of our customers as we can."
The company is also launching a number of products and initiatives designed to protect vulnerable customers and help them meet the rising cost of gas and electricity, he added.
E.ON's announcement has come after another energy supplier also unveiled price rises this week.
Scottish and Southern Energy is increasing the cost of its gas and electricity by 29.2 per cent and 19.2 per cent respectively.
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