Energia have announced a rise in their gas and electricity prices from August 1, 2018.
It means electricity prices will rise by 7.6%, or almost €83 a year for the average bill, while gas prices will increase by 12.38%, or almost €97 a year on average.
The energy company said the increase is "in response to a significant rise in wholesale energy costs".
The company said: "We work hard to offer our customers the very best value possible, however this decision to increase energy prices is unfortunately unavoidable due to an increase in the broader wholesale price of energy.
"Current customers can contact our customer service helpline on 1850 405 405 to discuss our best current customer deals."
The Head of Communications for energy price comparison website bonkers.ie, Daragh Cassidy, said: “Energia is now the fourth energy supplier to announce a price hike in June alone, after SSE Airtricity, Electric Ireland, and Flogas announced increases earlier in the month. So the question now is, who’s next?
"And at 7.6%, the electricity price increase is the largest to be announced so far this summer.
"But all these increases will definitely be felt by customers as we move into the winter months.
"Customers looking to offset price increases should be aware that the quickest and easiest way to do so is to compare suppliers and switch to the cheapest rate on the market. Right now, customers on typical standard rates, using an average amount of energy per year could save hundreds on their annual energy bills just by switching suppliers,” Mr Cassidy said.
Eoin Clarke, Managing Director of Switcher.ie, says: “As we feared, another round of energy price hikes is definitely upon us now.
“Any price increase is bad news, but this latest round of hikes has been particularly high - for example, an average customer who has a dual fuel plan with Energia will see their annual bill rise by €180.
“If you’re going to be impacted by these hikes, we would strongly encourage you to shop around for a new deal now. The average dual fuel customer can save up to €342 by switching from standard tariffs to the cheapest deals on the market, so this could help to soften the impact of the rises.
"You could also consider a fixed-rate energy plan. These generally don’t offer as low a rate as discounted variable tariffs, but there is still value to be had, and you’ll be insulated from price increases for the duration of your contract, which could give you some peace of mind.”