Panda Power and Pinergy have become the latest energy companies to announce an increase in their prices.
Panda Power said it will increase its standard unit rate electricity price by 5.9% and its gas price by 5%.
It is believed the increases will add almost €48 a year to the average customer's electricity bill and €32 a year to the average gas bill.
Pinergy, meanwhile, has announced a 9.38% increase in its electricity price, which will add around €72 a year to the average bill.
The increases at both companies will take effect from August 1.
Customers of Energia, Flogas, SSE Airtricity and Electric Ireland will also see their energy bills rise in the coming weeks, after the suppliers announced price hikes recently.
The companies said they were increasing their prices to the rising cost of gas and oil on the wholesale international markets.
Eoin Clarke, Managing Director of Switcher.ie, said there are only 10 energy suppliers in the market, and it is likely the remaining four will also announce similar hikes.
"Any increase in energy prices is really bad news for consumers, especially when you consider that energy is a household essential that we can't live without," Mr Clarke said.
"The average dual fuel bill for customers on standard tariffs already stands at almost €1,800 per year, which makes up a big chunk of many households' outgoings, and it seems this price is only going to go up," he cautioned.