Electric Ireland's increasing residential gas and electricity prices from the 1st of August.
Electricity bills are set to rise by 10.9% and gas bills by 29.2%.
Interim Executive Director Suzanne Ward says it understands the price increase is unwelcome news and it delayed the increase for as long as possible.
The company's blaming the situation in eastern Europe and a reduction in the reliability of gas flows, leading to sustained higher energy costs throughout Europe.
Over 1.2 million households across the country are set to be impacted.