PrepayPower is to increase its electricity prices by 8.8% and its gas prices by 10.6% for customers from the beginning of next month.
The pay-as-you-go electricity and gas provider said it has been "forced" to hike its prices due to "the increase in wholesale energy costs arising from the conflict in the Middle East".
The company estimates that for an average household this will add €3.23 per week to electricity bills and €3.28 to gas bills.
This would equate to nearly €168 extra per year for average electricity bills and €170 annually for average gas bills.
PrepayPower has around 180,000 electricity customers and 60,000 gas customers.
This will be the provider's first price increase in three and a half years.
Commenting on the increase, Daragh Cassidy from comparison website bonkers.ie said the news "isn't surprising to be honest".
"Last autumn, most of the energy suppliers hiked their electricity prices by between 10% and 15% as a result of continued high wholesale electricity costs and an increase in grid and network charges.
"However, PrepayPower, its sister company Yuno Energy, and Electric Ireland all announced a "price freeze" for the winter months.
"This meant that up until now, these suppliers' electricity prices were around 20% cheaper than the rest of the market. But this was always unlikely to last indefinitely. And to be honest, I’m surprised the electricity hike wasn’t a bit bigger.
"As a result of this, I’d also expect Electric Ireland, which has close to 1.1 million customers, to announce a similar hike in its electricity prices over the coming days or weeks.
"As for gas, wholesale prices are highly volatile, but they’re up around 40% to 50% since the start of the Iran war and are around three times the level they were at before the war in Ukraine broke out.
"Unfortunately, this was always likely to lead to a hike in gas bills eventually, and most of the other suppliers will probably follow with a similar hike over the coming weeks," Mr Cassidy added.
Commenting on the price increase, Managing Director of PrepayPower Eric Mullane said: "We've worked hard to protect our customers from rising energy costs - this is our first price increase in three and a half years, and last winter, whilst most other suppliers had to increase their rates, we went further by freezing prices when usage is at its highest.
"However, wholesale energy costs have continued to rise sharply, and it is simply not possible to hold out indefinitely. We will continue to do everything we can to minimise the impact on our customers and to help them control their energy costs."
