Northern Ireland gas supplier firmus energy announced that its customers in Belfast will see a 19.4% increase in their tariffs.
The change translates to an extra £2.75 a week on the average household bill, the company said.
It is predicted that an estimated 149,000 domestic customers will be impacted by the move.
One month ago, the company increased its natural gas tariff by 38.1% for customers living in the Ten Towns Network area.
Dr David Dobbin, Chairman of firmus energy, said: “We very much regret having to increase our Greater Belfast tariff however the sheer scale of the increases in global wholesale gas prices have forced our hand.
“We know this is an unwelcome increase which will have a disproportionate effect on those of our customers who are most vulnerable.
“This is not just a firmus issue, but one faced by energy suppliers across gas, oil and electricity, all of whom will have to increase their tariffs to meet the huge surge in global energy costs, if they haven’t already done so.”