The biggest electricity provider in Northern Ireland, Power NI has announced a 21.4% increase in prices.
That means that a typical household will pay £2.51 more every week starting from 1st January.
More than 20 energy suppliers in the UK have already folded since the start of September.
The company said the tariff change has been approved by the Utility Regulator and it will be applied only to domestic customers.
William Steele, Director at Power NI Customer Solutions, said: “We work very hard to keep our prices as low as possible, but regrettably there has been a rapid and sustained increase in wholesale gas prices over recent months.
“Like other suppliers, we have no choice but to pay these increased costs, which feed into the cost of wholesale electricity and have a knock-on effect on our tariffs.
“In these challenging times and with such a volatile market, we held off making this change for as long as possible, with this price change not coming into effect until January 2022. As soon as we see an opportunity to reduce prices, we will do so without delay.”